CVE-2026-3099

moderate-risk
Published 2026-03-12

A flaw was found in Libsoup. The server-side digest authentication implementation in the SoupAuthDomainDigest class does not properly track issued nonces or enforce the required incrementing nonce-count (nc) attribute. This vulnerability allows a remote attacker to capture a single valid authentication header and replay it repeatedly. Consequently, the attacker can bypass authentication and gain unauthorized access to protected resources, impersonating the legitimate user.

Do I need to act?

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0.54% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.8/10 Medium
NETWORK / HIGH complexity

Affected Vendors

33
/ 100
moderate-risk
Severity 18/34 · Moderate
Exploitability 2/34 · Minimal
Exposure 13/34 · Low