CVE-2026-5419 and is rated Low severity with a CVSS score of 3.7. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Jun 11, 2026
CBL-Mariner Releases
Vendor-listed releases
3.8.13-1
CISA KEVNot listedBased on the latest collected catalog
EPSS0.5%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-5419?
A flaw was found in gnutls. The PKCS#7 padding check, performed during decryption, was not constant-time.
This timing side-channel could allow a remote attacker to potentially leak sensitive information about the padding bytes through observable timing differences. This vulnerability is a form of information disclosure.