CVE-2026-3099

Name: CVE-2026-3099
Creator: NVD / NIST
Published: 2026-03-12T14:16:18.76+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.3/10EPSS 0.36%

Last modified Jun 17, 2026

CVE-2026-3099 is a high-severity vulnerability rated 7.3/10 on the CVSS scale. 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. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS Probability

0.36%

27.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-323

Affected Software

Vendor	Product	Versions
Gnome	Libsoup	All versions
Redhat	Enterprise Linux	6.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Redhat	Enterprise Linux	9.0
Redhat	Enterprise Linux	10.0

References

https://access.redhat.com/security/cve/CVE-2026-3099Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2442232Issue Tracking, Third Party Advisory
https://gitlab.gnome.org/GNOME/libsoup/-/issues/495Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Mar 12, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-3099?

How severe is CVE-2026-3099?

CVE-2026-3099 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3099?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-3099?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST