Vulnerability · Published Mar 13, 2026 · Assigned by GitHub_M
CVE-2026-32600xml-security 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 xml-security from simplesamlphp. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | simplesamlphp/xml-security | 2.3.1 | GHSA-r353-4845-pr5p |
| Packagist | simplesamlphp/xml-security | 1.13.9 | GHSA-r353-4845-pr5p |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| simplesamlphp | xml-security | >= 2.0.0, < 2.3.1< 1.13.9 |
Weakness: CWE-354 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
References
- https://github.com/simplesamlphp/xml-security/security/advisories/GHSA-r353-4845-pr5p x_refsource_CONFIRM
- https://github.com/simplesamlphp/xml-security/commit/cad6d57cf0a5a0b7e0cc4e4a5b18752e56eb1520 x_refsource_MISC
- https://github.com/simplesamlphp/xml-security/commit/fdc12449e959c610943f9fd428e95e3832d74c25 x_refsource_MISC