Vulnerability · Published Mar 13, 2026 · Assigned by GitHub_M

CVE-2026-32313xmlseclibs is Missing AES-GCM Authentication Tag Validation on Encrypted Nodes Allows for Unauthorized Decryption

High 8.2

In plain English

A high-severity security flaw in xmlseclibs from robrichards. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High
Exploit odds (30 days)0.2%top 95.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

xmlseclibs is a library written in PHP for working with XML Encryption and Signatures. Prior to 3.1.5, XML nodes encrypted with either aes-128-gcm, aes-192-gcm, or aes-256-gcm lack validation of the authentication tag length. An attacker can use this to brute-force an authentication tag, recover the GHASH key, and decrypt the encrypted nodes. It also allows to forge arbitrary ciphertexts without knowing the encryption key. This vulnerability is fixed in 3.1.5.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Packagistrobrichards/xmlseclibs3.1.5GHSA-4v26-v6cg-g6f9

Affected products (as reported)

VendorProductVersions
robrichards xmlseclibs < 3.1.5

Weakness: CWE-354 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

References