93 results · Feed
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Unscored —
Arbitrary command execution via GCC spec files in cgo linker search directories in cmd/go
When using GCC, building a malicious package that uses cgo could cause arbitrary command execution at link time via untrusted GCC spec files ("specs" or "*.spec"). When linking with "-fopenmp", "-fopenacc", or "-fsanitize=" in "#cgo LDFLAGS", GCC's built-in l…
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Unscored —
Unexpected code execution via --sysroot, -target, -isysroot, -Wl,-syslibroot, and -x cgo flags in cmd/go
Building a malicious package that uses cgo could cause arbitrary code execution at build time through several compiler and linker flags permitted in "#cgo" directives. Specifically, "--sysroot" in GCC and Clang relocates compiler subprograms, spec files, and …
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Unscored —
HTTP/1 server crash due to MaxBytesReader header race in net/http
For HTTP/1 servers, when MaxBytesReader's limit is exceeded, "Connection: close" header is automatically set without synchronization, which might race with another header being set explicitly in the server handler. As a result, an HTTP/1 server that utilizes …
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Unscored —
Linker script injection via split -Wl, flags and Darwin or symbol linker flags in cgo in cmd/go
Building a malicious package that uses cgo could cause arbitrary code execution at link time by passing linker script files to the host linker via "#cgo LDFLAGS". Split "-Wl," flags that consume a following argument (such as "-Wl,-rpath", "-Wl,--just-symbols"…
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Unscored —
Arbitrary code execution during build on darwin via "-l to_library" in cgo in cmd/go
On Darwin, building a malicious package that uses cgo could cause arbitrary code execution when using the Apple linker due to passing "-l to_library <path>" in a "#cgo LDFLAGS" directive. The Apple linker recombines the separated arguments "-l" and "to_librar…
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Unscored —
Unexpected code execution and arbitrary file write via Clang -gen-* and GCC -gnat* flags in cgo in cmd/go
When using Clang or GCC, building a malicious package that uses cgo could cause unexpected code execution at build time or write files to arbitrary directories via "-gen-*" or "-gnat*" flags in "#cgo" directives. The "-g*" wildcard in the compiler and linker …
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Unscored —
Linker flag injection via cgo_import_dynamic and PE DLL names in cmd/cgo, cmd/compile, and cmd/link
Building a malicious package that uses "//go:cgo_import_dynamic" or links against a crafted PE object on Windows could pass unsafe library arguments to the external linker. The compiler only checked the first character of the library name in "//go:cgo_import_…
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Unscored —
Host linker flag injection via //go:cgo_* directives in cmd/compile and cmd/link
Building a malicious package containing "//go:cgo_*" compiler directives could inject arbitrary flags into the external linker invocation on ELF platforms. The compiler and linker did not reject commas in "//go:cgo_import_dynamic", "//go:cgo_export_dynamic", …
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Unscored —
Cgo directive injection via .syso files disguised as Go object files in cmd/go and cmd/link
Building a package containing a crafted ".syso" file could bypass cgo flag validation and inject arbitrary linker flags when linking. When loading ".syso" entries from a package archive, the linker only checked for recognized host object headers (ELF, Mach-O,…
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Unscored —
Flag sanitization bypass via "#cgo pkg-config:" directives in cmd/go
Building a malicious package that uses "#cgo pkg-config:" directives could load untrusted pkg-config ".pc" files or inject unvalidated compiler and linker flags. The pkg-config flag allowlist previously permitted "--with-path=" and "--personality=", allowed "…
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Unscored —
Arbitrary code execution via crafted .syso files and cgo linker input files in cmd/go
Building a malicious package containing ".syso" files or cgo linker inputs could inject arbitrary linker flags or execute arbitrary code at link time. Linker input files—including ".syso" files, direct object or library inputs in "#cgo LDFLAGS", and libraries…
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Unscored —
Unexpected code execution via escaped quotes in //go:cgo_ldflag in cmd/go and cmd/compile
Building a malicious package that uses cgo could bypass "#cgo LDFLAGS" validation and cause unexpected code execution at build time, or cause the go command to panic, via crafted quoting in "//go:cgo_ldflag" directives. When "cmd/cgo" generates "_cgo_gotypes.…
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Medium 6.8CVE-2026-111943 Public exploit
Distrust compromised intermediate certificates in crypto/x509
On most platforms, Go uses the given system root certificates. However, in some narrower cases, the system trust stores may not be updated without further action. To defend against the narrower set of cases that may remain affected, a denylist was added in cr…
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High 7.5
HTTP/2 server crash due to HPACK encoder race in net/http
HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently. This happens because the server modifies the HPACK encoder from two goroutines without synchronization: one uses the encoder to encode a HEADERS frame as part …
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High 7.5
HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http
When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the …
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High 7.5
Lack of limit on size of parsed Range headers in net/http
When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) can consume an excessive amount of CPU.
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High 7.5
HTTP/2 transport accepts malformed framing-related headers in net/http
Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such header…
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Critical 9.1
Double flow control refund on HTTP/2 server streams in net/http
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client…
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High 7.5
Excessive CPU consumption from repeated initial window changes in net/http
A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.
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High 7.5
Memory limit bypass when parsing MIME headers in net/textproto, mime/multipart
Parsing a multipart form can bypass memory limits and read an arbitrarily long line into memory when the remaining limit at the start of a part is less than 400 bytes.
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High 7.5
Reject malformed ECH outer extension references in crypto/tls
Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject these as malformed and …
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High 7.5
HTTP/1 client connection desynchronization after CONNECT rejection in net/http
When http.Transport sends an HTTP/1 CONNECT request with a non-empty Request.Body, it writes the body directly to the connection without framing after the request headers. If the server rejects the CONNECT request with a non-2xx keep-alive response, Transport…
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High 7.5
HTTP/2 server memory exhaustion due to Trailer headers in net/http
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicio…
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Medium 6.1
Reset context tracking on consecutive template expressions in html/template
When a JavaScript template literal contains consecutive expressions, the context tracking state was not properly reset upon entering a new expression. We now ensure that template-literal expression entries correctly reset context variables so all subsequent r…
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High 7.8
Checksum bypass for golang.org/fips140 in cmd/go
Previously, a user operating inside of a malicious Go project that defines a bogus golang.org/fips140 and operates a malicious GOMODPROXY the user chooses to connect to can serve an arbitrary module in its place. We now unpack the trusted ziphash for the bund…
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High 7.8
Checksum database bypass for golang.org/toolchain in cmd/go
Previously, a user operating inside of a malicious Go project that defines a bogus golang.org/toolchain go.sum entry and operates a malicious GOMODPROXY the user chooses to use can bypass the intended checksum. We now ensure that golang.org/toolchain always g…
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Medium 6.1
Recognize yield as regexp preceder keyword in html/template
A trusted template author may have previously written a valid template wherein the use of the 'yield' keyword would not be correctly escaped. We now ensure that valid keyword uses are escaped and non-keyword uses are not escaped.
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High 8.4
Fix transparency log tile verification bypass in golang.org/x/mod/sumdb/tlog
A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go module cache. This attack allows for a malicious GOPROXY to …
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Medium 5.9
Avoid quadratic complexity in resolvePath in net/url
Previously, resolving relative paths containing parent directory ('..') segments performed string conversions and buffer rewrites on each step, resulting in quadratic time complexity and high memory allocation overhead. Now, path resolution operates on a byte…
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High 7.5
Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb
A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the trans…
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High 7.5
Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http
When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.
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High 7.5
Limit handshake messages we are willing to accept post-handshake in crypto/tls
Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key deriva…
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Medium 6.1
Fix Javascript regexp context tracking in html/template
Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
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High 7.5
Add recursion depth guard during decode in encoding/xml
Previously, DecodeElement would reset the depth counter causing it to never fire; this could lead to stack exhaustion.
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High 7.5
Enforce maximum recursion depth in encoding/asn1
Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested, recursive structures.
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Medium 5.3
Invoking Encrypted Client Hello privacy leak in crypto/tls
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
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High 7.8
Root escape via symlink plus trailing slash in os
On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even whe…
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Medium 5.3
Arbitrary inputs are included in errors without any escaping in net/textproto
When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.
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High 7.5
Quadratic complexity in WordDecoder.DecodeHeader in mime
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
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Medium 6.5CVE-2026-27145 Public exploit
Inefficient candidate hostname parsing in crypto/x509
(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, ".") to execute repeatedly on the same input hostname. With a large DNS SAN list, verification c…