High severity · published Mar 13, 2026
CVE-2026-32313
xmlseclibs is Missing AES-GCM Authentication Tag Validation on Encrypted Nodes Allows for Unauthorized Decryption
8.2
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XM
xmlseclibs · robrichards
< 3.1.5 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-32313
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-32313
Patch
https://github.com/robrichards/xmlseclibs/commit/03062be78178cbb5e8f605cd255dc32a14981f92
Product
https://github.com/robrichards/xmlseclibs/releases/tag/3.1.5
Exploit
https://github.com/robrichards/xmlseclibs/security/advisories/GHSA-4v26-v6cg-g6f9
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