EUVD-2026-21292
GHSA-3xr8-r75g-g9c6
Severity by source
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
7DescriptionCVE.org
In wolfSSL's EVP layer, the ChaCha20-Poly1305 AEAD decryption path in wolfSSL_EVP_CipherFinal (and related EVP cipher finalization functions) fails to verify the authentication tag before returning plaintext to the caller. When an application uses the EVP API to perform ChaCha20-Poly1305 decryption, the implementation computes or accepts the tag but does not compare it against the expected value.
AnalysisAI
ChaCha20-Poly1305 AEAD decryption in wolfSSL's EVP layer bypasses authentication tag verification, allowing unauthenticated adjacent attackers to inject arbitrary ciphertext that is decrypted and returned as plaintext without cryptographic validation. Affects wolfSSL versions prior to 5.9.1. Applications using EVP API for ChaCha20-Poly1305 decryption receive potentially malicious plaintext, enabling man-in-the-middle attacks that compromise confidentiality and integrity of encrypted communications. No public exploit identified at time of analysis, low observed exploitation activity (EPSS <1%).
Technical ContextAI
Root cause in wolfSSL_EVP_CipherFinal and related EVP cipher finalization functions (CWE-354: improper integrity check). Implementation computes/accepts Poly1305 authentication tag but omits comparison against expected value, violating AEAD security contract. Adjacent network vector (AV:A) requires attacker proximity to manipulate encrypted traffic in transit.
RemediationAI
Vendor-released patch: upgrade to wolfSSL 5.9.1 or later, which implements proper tag verification in EVP cipher finalization path. Organizations unable to upgrade immediately should disable ChaCha20-Poly1305 cipher suites in wolfSSL configurations and migrate to alternative AEAD algorithms (AES-GCM) until patching is feasible. Review application logs for anomalous decryption patterns that may indicate exploitation attempts. Upstream fix details available at https://github.com/wolfSSL/wolfssl/pull/10102. Prioritize patching for adjacent-network deployments (wireless, shared infrastructure) where AV:A vector is viable.
wolfSSL prior to version 3.12.2 provides a weak Bleichenbacher oracle when any TLS cipher suite using RSA key exchange i
A specially crafted x509 certificate can cause a single out of bounds byte overwrite in wolfSSL through 3.10.2 resulting
wolfSSL (formerly CyaSSL) before 3.6.8 allows remote attackers to cause a denial of service (resource consumption or tra
In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3 handshake. Rated high severity (
An issue was discovered in wolfSSL before 5.5.0. Rated high severity (CVSS 7.5), this vulnerability is remotely exploita
wolfSSL 4.3.0 has mulmod code in wc_ecc_mulmod_ex in ecc.c that does not properly resist timing side-channel attacks. Ra
In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data wh
An issue was discovered in wolfSSL before 4.5.0, when single precision is not employed. Rated high severity (CVSS 7.0).
wolfSSL before 4.5.0 mishandles TLS 1.3 server data in the WAIT_CERT_CR state, within SanityCheckTls13MsgReceived() in t
wolfSSL (formerly CyaSSL) before 3.6.8 does not properly handle faults associated with the Chinese Remainder Theorem (CR
An issue was discovered in wolfSSL before 5.5.0 (when --enable-session-ticket is used); however, only version 5.3.0 is e
wolfSSL 4.6.x through 4.7.x before 4.8.0 does not produce a failure outcome when the serial number in an OCSP request di
Same technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today