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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-13758 Detail

Description

CryptX versions before 0.088_001 for Perl compare AEAD authentication tags in non-constant time in the streaming decrypt_done path. The decrypt_done($tag) form compares it against the computed tag with memNE (memcmp() != 0), which short-circuits on the first differing byte, so its run time depends on the number of matching leading bytes. This affects all five AEAD modes: GCM, CCM, ChaCha20Poly1305, EAX and OCB. The one-shot *_decrypt_verify helpers are unaffected; they verify the tag inside libtomcrypt with a constant-time comparison. The timing difference is a tag-verification oracle. An attacker who can submit many candidate tags for the same nonce, ciphertext and associated data while measuring the timing precisely enough may recover the expected tag byte by byte and forge a message that verifies.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
http://www.openwall.com/lists/oss-security/2026/06/29/19 CVE
https://github.com/DCIT/perl-CryptX/commit/7e56347d420aaf43b2ee1586f4a230492ccf1642.patch CPANSec
https://metacpan.org/release/MIK/CryptX-0.088_001/changes CPANSec

Weakness Enumeration

CWE-ID CWE Name Source
CWE-208 Observable Timing Discrepancy CPANSec  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-13758
NVD Published Date:
06/29/2026
NVD Last Modified:
06/29/2026
Source:
CPANSec