Weakness (CWE)
CWE-20: Improper Input Validation
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
How to prevent it (8 mitigations)
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Architecture and Design
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
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Architecture and Design
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
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Architecture and Design, Implementation
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
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Implementation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
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Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
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Implementation
When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
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Implementation
Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
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Implementation
Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
Source: MITRE CWE-20
6,595 results · Feed
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Medium 4.3
HCL BigFix Service Management is affected by multiple security vulnerabilities.
HCL BigFix Service Management is affected by an Improper Input Validation vulnerability, which could allow an attacker to inject unvalidated, malformed data into the application, enabling potential injection attacks or errors in downstream processing systems.
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High 8.7
Taskcluster: Unauthenticated remote code execution in `web-server` via GraphQL `filter` argument (sift `$where`)
Taskcluster is the task execution framework that supports Mozilla's continuous integration and release processes. Prior to version 100.3.0, Taskcluster is vulnerable to unauthenticated RCE on Taskcluster deployments with an anonymous role that exposes the Gra…
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the firmware where an attacker could cause …
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the firmware where an attacker could cause …
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Medium 6.7
VIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker coul…
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker cou…
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker cou…
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Medium 6.2
MISP Stored Cross-Site Scripting via Unvalidated Galaxy Icon Field in Correlation Graph
MISP contains a stored cross-site scripting (XSS) vulnerability in the galaxy icon handling path. The icon field of a galaxy object was persisted without any server-side validation through the galaxy add, edit, and sync/import capture endpoints. The stored va…
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High 8.3
MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature. The event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img ele…
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High 7.5
Apache WSS4J: Insufficient Validation of Derived-Key Parameters
Apache WSS4J accepted attacker-controlled derived-key lengths and offsets without adequate bounds. This could permit cryptographically weak keys or excessive CPU and memory consumption when processing crafted WS-Security messages. The fixes enforce a minimum …
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High 8.3
MISP: Nested Model Alias Key Bypasses Sanitization to Modify Cross-Tenant Rows
MISP contains an improper input validation vulnerability in its ORM save path. When a user submits data through various endpoints (attribute add/edit, event edit, free-text import, sighting capture, shadow attribute proposal, event report creation, object ref…
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Medium 6.5
Apache MINA SSHD: Remote execution of JGit "archive -o=file.zip" can write file on the server
Improper input validation in sshd-git in Apache MINA SSHD, versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5. Apache MINA SSHD is a Java library for client-side and server-side SSH. Component org.apache.sshd:sshd-git provides though class GitPgmCommandFactory a …
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High 7.5
russh: Client-side channel-scoped Handler callbacks fire for channel IDs the client never opened
Russh is a Rust SSH client and server library. Prior to 0.63.1, client_read_authenticated in russh/src/client/encrypted.rs forwards CHANNEL_DATA, CHANNEL_EXTENDED_DATA, CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_OPEN_FAILURE, CHANNEL_SUCCESS, CHANNEL_FAILURE, and CH…
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High 7.8
Electron: Sandboxed preload code cache can be poisoned by a compromised renderer
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. From 42.3.3 until 42.10.0, 43.5.0, and 44.0.0-beta.6, Electron's sandboxed preload code cache did not verify that a cached entry matched the preload it was…
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Medium 5.4
Improper input validation in Passwords in Google Chrome prior to 154.0.8037.57 allowed a remote attacker to spoof UI el…
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High 8.3
Improper input validation in Desktop in Google Chrome prior to 154.0.8037.57 allowed a remote attacker who had compromi…
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High 8.3
Improper input validation in Themes in Google Chrome prior to 154.0.8037.57 allowed a remote attacker who had compromis…
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High 8.3
Improper input validation in Printing in Google Chrome prior to 154.0.8037.57 allowed a remote attacker who had comprom…
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Medium 6.5
Improper input validation in Auth in Google Chrome prior to 154.0.8037.57 allowed a remote attacker who had compromised…
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High 7.5
Socket.IO: Prototype Pollution via Unsafe Client Session Lookup
Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 0.1.1, @socket.io/cluster-engine uses inherited object properties when looking up attacker-controlled session IDs in clustered deployments. Special property names such …
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Critical 9.6
Sandbox escape in the XUL component
Sandbox escape in the XUL component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.
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Low 1.3
Checkout validation bypass
A logic flaw in the checkout flow allows users to bypass validations performed during the check-in by skipping entire check-in steps.
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Low 3.6
Flatpak: flatpak: denial of service via unsanitized keys in exported desktop entry / d-bus service files
Flatpak passes through arbitrary vendor-extension keys unmodified when exporting an application's Desktop Entry (.desktop) and D-Bus Service (.service) files, instead of validating against an allowlist. A malicious Flatpak app can use this to cause denial of …
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Medium 4.7
DOMSanitizer - Incomplete data: URL Sanitization in DOMSanitizer::isDangerousUrl() Allows Base64-Encoded Payloads to Bypass href and xlink:href Validation
DOMSanitizer is a DOM/SVG/MathML Sanitizer for PHP 7.3+. Prior to version 1.0.15, the isDangerousUrl() method is responsible for rejecting dangerous URL values in the href and xlink:href attributes. The weakness is that "javascript:" is rejected as a scheme, …
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Critical 9.8CVE-2026-96760 Public exploit
Authlib library contains a signature‑verification bypass vulnerability
Authlib (v1.8.0 and below) contains a signature verification bypass vulnerability. The JsonWebSignature.deserialize_json() method accepts a JSON Serialization JWS object and returns the payload as successfully verified without checking for a signature and wit…
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Medium 4.3
Insufficient validation of untrusted input in Codecs in Google Chrome prior to 147.0.7727.55 allowed a remote attacker …
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Low 3.3
deepseek-ai deepseek-harness dsh index.ts reliance on untrusted inputs in a security decision
A vulnerability was identified in deepseek-ai deepseek-harness up to 0.1.5-rc.3. Impacted is an unknown function of the file packages/e2b/e2b/src/index.ts of the component dsh. The manipulation of the argument E2B_API_KEY leads to reliance on untrusted inputs…
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High 8.6
FreePBX: Authenticated Superfecta Arbitrary PHP Code Execution (RCE via Unsafe File Inclusion)
FreePBX is an open source IP PBX. Prior to versions 16.0.40 and 17.0.7, a critical remote code execution (RCE) vulnerability exists in the superfecta module due to unsafe inclusion of arbitrary PHP files, allowing authenticated attackers to execute arbitrary …
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Critical 9.6
SailPoint IdentityIQ Improper Form Validation Vulnerability
This vulnerability impacts all versions of IdentityIQ and allows an unauthenticated user remote code execution on the IdentityIQ server due to improper input validation of submitted web service API content.
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Low 2.8
agentverus agentverus-scanner context.js isSecurityDefenseSkill reliance on untrusted inputs in a security decision
A vulnerability was found in agentverus agentverus-scanner up to 0.8.1. Affected by this vulnerability is the function isSecurityDefenseSkill of the file dist/scanner/analyzers/context.js. Performing a manipulation results in reliance on untrusted inputs in a…
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High 7.2
Authenticated PowerShell Injection in DNS Query Resolution Policy leads to RCE
ManageEngine DDI Central versions below 6201 are vulnerable to Command injection in Windows DNS Query Resolution Policy name field leading to remote code execution.
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High 8.8
Authenticated PowerShell Injection leads to RCE
ManageEngine DDI Central versions below 6201 are vulnerable to PowerShell command injection in Windows DNS SPF/TXT record push leading to remote code execution.
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High 7.3
Trusted Domain Project OpenDMARC policy.c improper validation of unsafe equivalence in input
A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this issue is some unknown functionality of the file policy.c of the component Domain Handler. Executing a manipulation can lead to improper validation of unsafe equivalence in…
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High 7.3
OctoberCMS ResizeImages.php getSourcePathForResize server-side request forgery
A vulnerability was found in OctoberCMS up to 4.1.19/4.2.25/4.3.4. The impacted element is the function getSourcePathForResize of the file modules/system/classes/ResizeImages.php. The manipulation of the argument realSourcePath results in server-side request …
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Medium 6.5
Barco ClickShare CX-20 Gen2 Wallpaper Upload wallpaper improper validation of syntactic correctness of input
A vulnerability was determined in Barco ClickShare CX-20 Gen2 up to 02.26.00.0007. Affected by this issue is some unknown functionality of the file /wallpaper of the component Wallpaper Upload. This manipulation of the argument wallpaper causes improper valid…
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High 7.0CVE-2026-88774 Public exploit
Feature policy bypass due to improper HTTP URL based expression usage
Vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23 leading to a feat…
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Critical 9.5
A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commands
Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13…
KEV Sep 27, 2026 -
Medium 6.3
Vulnerability-Lookup - Race Condition in Account Recovery Token Consumption Allows Password Takeover
The account recovery (password reset) functionality in the vulnerability-lookup web application contains a time-of-check-to-time-of-use (TOCTOU) race condition in the consumption of single-use recovery tokens. The original implementation verified the token no…
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Critical 9.6CVE-2026-100833 Public exploit
Contrast before 1.23.1 Image Substitution via Policy Generation
Contrast (edgelesssys/contrast) versions 1.14.0 before 1.23.1 generate runtime policies that fail to detect all container image substitutions. A bad rebase during a Kata Containers update accidentally introduced an `allow_storage` rule that accepts storage en…
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Medium 5.3
Nodemailer before 10.0.9 Malformed Envelope Recipient via RFC 5322 Comment
Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated d…