CVE-2026-63072 Affecting openssl package, versions <3.5.7-1~deb13u2


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.61% (47th percentile)

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  • Snyk IDSNYK-ECHOLATEST-OPENSSL-19267915
  • published26 Aug 2026
  • disclosed25 Aug 2026

Introduced: 25 Aug 2026

NewCVE-2026-63072  (opens in a new tab)

How to fix?

Upgrade Echo:latest openssl to version 3.5.7-1~deb13u2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports, causing an 8-byte out-of-bounds heap write.

Impact summary: An attacker who supplies a crafted CMS message can trigger a deterministic 8-byte out-of-bounds heap write when the victim decrypts it with CMS_decrypt(), corrupting the heap and typically resulting in a Denial of Service.

CWE: CWE-787: Out-of-bounds Write

Description: The key-wrap OID is potentially attacker-controlled on the wire. CMS unwrapping allows both id-aesNNN-wrap-pad and id-aesNNN-wrap ciphers. An attacker can take a legitimate message and change a single OID byte to select the padded variant while leaving the message otherwise valid. Since the unwrap key is derived from the recipient's private operation (ECDH key agreement or ML-KEM decapsulation), the RFC 5649 integrity check cannot pass, and the decryption fails with integrity failure.

The write is a fixed-size (8-byte), fixed-value (zero) heap overflow immediately past the allocation, requires no special configuration, and is reachable from the public CMS_decrypt() function. The consequence is a heap corruption leading to a Denial of Service. The fix in the CMS code sizes the unwrap output buffer for the worst case so a failed unwrap cannot write past the allocation.

FIPS impact: no

As the CMS code lives outside the FIPS module boundary, no FIPS modules are affected by this CVE.

CVSS Base Scores

version 3.1