What’s Vulnerable › Vulnerabilities

CVE-2026-32600: xml-security is Missing AES-GCM Authentication Tag Validation on Encrypted Nodes Allows for Unauthorized Decryption

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-16 · updated 2026-06-17
• Weakness: CWE-354

Description

xml-security is a library that implements XML signatures and encryption. Prior to versions 2.3.1 and 1.13.9, 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 2.3.1 and 1.13.9.

Affected products

• simplesamlphp xml-security: before 1.13.9; from 2.0.0 before 2.3.1 — fixed in 1.13.9, 2.3.1

How to fix

Upgrade to a fixed version: simplesamlphp xml-security 1.13.9, 2.3.1. Check the vendor advisory for mitigations.

References

• https://github.com/simplesamlphp/xml-security/commit/cad6d57cf0a5a0b7e0cc4e4a5b18752e56eb1520
• https://github.com/simplesamlphp/xml-security/commit/fdc12449e959c610943f9fd428e95e3832d74c25
• https://github.com/simplesamlphp/xml-security/security/advisories/GHSA-r353-4845-pr5p

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