CVE-2026-34182
Description
A flaw was found in OpenSSL's Cryptographic Message Services (CMS) AuthEnvelopedData processing. An on-path attacker can exploit insufficient input validation on cipher and tag length fields by sending specially crafted CMS messages. This can lead to the forging of messages or bypassing integrity validation. Consequently, an attacker may achieve key-equivalent functionality for a given CMS recipient.
Statement
Moderate: This flaw in OpenSSL's Cryptographic Message Services (CMS) AuthEnvelopedData processing could allow an on-path attacker to forge messages or bypass integrity validation. This is due to insufficient input validation on cipher and tag length fields, potentially leading to key-equivalent functionality or integrity bypass in applications utilizing affected OpenSSL versions for CMS AuthEnvelopedData.
Mitigation
Systems configured to operate in FIPS mode are not affected by this vulnerability. To mitigate this issue, ensure that OpenSSL is operating in FIPS mode by enabling the system-wide FIPS policy. This may have broader implications for cryptographic operations on the system and should be evaluated for compatibility with existing applications. A system reboot may be required for the changes to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | N/A | 9.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality,Integrity
Technical Impact: Read Memory; Modify Memory; Varies by Context
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