CVE-2026-34182

Aliases:DEBIAN-CVE-2026-34182UBUNTU-CVE-2026-34182ALPINE-CVE-2026-34182CGA-2wwv-w5xp-m9x8CGA-4gg8-v3p2-g8wvCGA-cqrg-76ch-37jwCGA-3qrf-g3rj-5328CGA-569x-78w8-m8qrCGA-5h24-476x-8m77CGA-9q2f-9wmc-r8cwCGA-g6f2-jvrf-2967CGA-gjq3-6fg9-5m9xCGA-mp4r-j6qw-phxvCGA-r77q-m4fj-g6vfCGA-v77x-mff6-j494CGA-vrqg-g65v-4vmjCGA-x99c-q37q-g6fj
Advisory lineage Upstream: 0 Downstream: 18
Analyzed
Published: 09 Jun 2026, 16:03
Last modified:10 Jun 2026, 15:58

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.1 CRITICAL
v3.1 (cve.org)
EPSS Score
0.61% LOW
1% probability +0.17%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

09 Jun 2026, 16:03
Published
Vulnerability first disclosed
10 Jun 2026, 15:58
Last Modified
Vulnerability information updated

Description

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 these vulnerabilities may achieve key-equivalent functionality for a given CMS recipient and/or bypass integrity validation for a given message. In one use case, an attacker may send a CMS message containing AuthEnvelopedData with the cipher specified as a non-AEAD cipher. OpenSSL erroneously allows this selection, and attempts to decrypt and validate the message. An on-path attacker who captures one legitimate AES-GCM AuthEnvelopedData addressed to the victim can re-emit it with the recipientInfos set left byte-for-byte intact, so the victim's private key still unwraps the genuine CEK (the content-encryption key), but with the inner OID rewritten to AES-256-OFB (Output Feedback Mode, an unauthenticated keystream mode) and with an attacker-chosen IV and ciphertext. The victim initializes AES-256-OFB under the real CEK, never consults the MAC field, and CMS_decrypt() returns success. If the application under attack responds to the attacker with any indicator showing success or failure of the decryption effort, it is possible for the attacker to use this as an oracle to obtain key equivalent functionality for the CEK used for the chosen recipient of the message. In another use case, an attacker can reduce the tag length of the chosen AEAD cipher for a given AuthEnvelopedData container to be a single byte long, allowing an attacker to brute force CMS decryption, producing an integrity bypass for applications that trust CMS_decrypt() to reject modified content. The FIPS modules are not affected by this issue.

CVSS Metrics

  • v3.1•CRITICAL•Score: 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS Trends

Current EPSS score: 0.61%• Percentile: 48%

Techniques & Countermeasures

  • CWE-354•Improper Validation of Integrity Check Value

    The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.

Affected Systems

  • alpine•openssl

    ≥ 3.0.0, < 3.3.7-r1 | ≥ 3.0.0, < 3.5.7-r0 | ≥ 3.0.0, < 3.5.7-r0 | ≥ 3.0.0, < 3.5.7-r0

  • chainguard•libcrypto3

    < 3.6.3-r0

  • chainguard•libcrypto3-2.34

    < 3.6.3-r0

  • chainguard•openssl

    < 3.6.3-r0

  • chainguard•openssl-provider-fips-3.4.0

    < 0

  • chainguard•openssl-provider-fips-3.4.0-dbg

    < 0

  • chainguard•openssl-provider-fips-3.6.0

    < 0

  • chainguard•openssl-provider-fips-3.6.0-dbg

    < 0

  • wolfi•libcrypto3

    < 3.6.3-r0

  • wolfi•openssl

    < 3.6.3-r0

  • debian•openssl

    < 3.0.20-1~deb12u2 | < 3.5.6-1~deb13u2 | < 3.6.3-1

  • ubuntu•edk2

    all | all | all

  • ubuntu•edk2-hwe

    all

  • ubuntu•nodejs

    all

  • ubuntu•openssl

    < 3.0.2-0ubuntu1.25 | all | < 3.0.2-0ubuntu1.25+Fips1 | < 3.0.13-0ubuntu3.11 | < 3.5.3-1ubuntu3.4 | < 3.5.5-1ubuntu3.2

  • ubuntu•openssl-fips

    all | < 3.0.13-0ubuntu3.12+Fips1

  • openssl•openssl

    ≥ 4.0.0, < 4.0.1 | ≥ 3.0.0, < 3.0.21 | ≥ 3.4.0, < 3.4.6 | ≥ 3.5.0, < 3.5.7 | ≥ 3.6.0, < 3.6.3 | 4.0.0

References (19)