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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-32313

An attacker can use this to brute-force an authentication tag, recover the GHASH key, and decrypt the encrypted nodes.

HIGH 8.2EPSS 0.16%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS
0.16% probability · 5th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-354
Affected
xmlseclibs project/xmlseclibs
Source
security-advisories@github.com
EPSS trend
0%3%5%27 October 2026: 0.16%27 October 202627 October 2026

EPSS 0.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.