Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-9076: Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of Service for an application if the input buffer ends at a memory page boundary and the following page is unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap allocation that is based on the wrapped key length from the message. There is a minimum length check based on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-read is limited to a few bytes and is not written to output, so there is no information disclosure. Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal allocator. The FIPS modules are not affected by this issue. CVE-2026-7383: Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead to a crash or possibly attacker controlled code execution or other undefined behaviour. In ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary. CVE-2026-45447: Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO usage patterns, this may result in a crash or other memory corruption. In some application contexts this may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary. CVE-2026-45446: Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update, which can happen when the received ciphertext length is zero, the tag is never recalculated and still holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context without resetting the key. AES-SIV is imple
Fixed packages 11
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | openssl | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-debuginfo | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-debugsource | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-devel | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-fips-provider-latest | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-fips-provider-latest-debuginfo | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-libs | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-libs-debuginfo | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-perl | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-snapsafe-libs | 1:3.5.5-1.amzn2023.0.5 |
| Amazon Linux · 2023 | openssl-snapsafe-libs-debuginfo | 1:3.5.5-1.amzn2023.0.5 |
Vulnerabilities 15
-
Critical 9.1
CMS AuthEnvelopedData Processing May Accept Forged Messages
Issue Summary: Cryptographic Message Services (CMS) processing fails to perform sufficient input validation on the cipher and tag length fields of AuthEnvelopedData containers, leading to various potential compromises. Impact Summary: Attackers making use of …
-
High 8.8CVE-2026-45447 Public exploit
Heap Use-After-Free in the PKCS7_verify() Function
Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap corruption, or potentially remote code execution. When…
-
High 8.1
Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion
Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead to a crash or possibly attacker controlled code executi…
-
High 7.5
Heap Buffer Over-read in ASN.1 Content Parsing
Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms. Impact summary: The heap buffer over-read may crash the…
-
High 7.5
Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler
Issue summary: Remote peer may exhaust heap memory of the QUIC server or client by flooding it with packets containing PATH_CHALLENGE frames. Impact summary: A malicious remote peer can cause an unbounded memory allocation which can lead to an abnormal termin…
-
High 7.5
NULL Pointer Dereference in QUIC Server Initial Packet Handling
Issue summary: Receiving a QUIC initial packet with an invalid token may trigger a NULL pointer dereference in the OpenSSL QUIC server with address validation disabled. Impact summary: NULL pointer dereference typically causes abnormal termination of the affe…
-
High 7.5
AES-OCB IV Ignored on EVP_Cipher() Path
Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary: Every message encrypted under the same key uses the sam…
-
High 7.5
Out-of-Bounds Read in CMS Password-Based Decryption
Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in kek_unwrap_key(). Impact summary: A heap buffer over-read m…
-
High 7.4
PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys
Issue Summary: The PKCS#12 file processing fails to perform sufficient input validation for files that use Password-Based Message Authentication Code 1 (PBMAC1) integrity mechanism allowing a certificate and private key forgery. Impact Summary: An attacker im…
-
Medium 5.9
Possible NULL Dereference in Password-Based CMS Decryption
Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service. The CMS PasswordRecipientInfo.…
-
Medium 5.9
NULL Pointer Dereference in CRMF EncryptedValue Decryption
Issue summary: An attacker-controlled CMP (Certificate Management Protocol) server could trigger a NULL pointer dereference in a CMP client application. Impact summary: A NULL pointer dereference causes a crash of the application and a Denial of Service. An a…
-
Medium 5.3
Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate
Issue Summary: An error in the callback used to verify the certificate provided in a Root CA key update Certificate Management Protocol (CMP) message response rendered the certificate validation ineffectual, which could lead to escalation of credentials from …
-
Medium 4.8
Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes
Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such messages. Impact summary: An attacker can forge empty m…
-
Low 3.7
Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
Issue summary: The CMS_decrypt and PKCS7_decrypt functions are vulnerable to Bleichenbacher-style attack when an attacker is able to provide the CMS or S/MIME messages and observe the error code and/or decryption output. Impact summary: The Bleichenbacher-sty…
-
Low 3.7
FFC-DH Peer Validation Uses Attacker-Supplied q
Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership. Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a fo…
References
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-34180.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-34181.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-34182.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-34183.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42764.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42766.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42767.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42768.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42769.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-42770.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-45445.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-45446.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-45447.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-7383.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-9076.html