Vulnerability Report

CVE-2026-3099

Title: Libsoup digest authentication replay vulnerability

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2026-3099.

CWE Category CWE-323

Published Date Mar 12, 2026

Modified Date Mar 23, 2026

Exploit Status Not Found

Score 5.8 CVSS v3.1

Exploit Probability (EPSS)

0.46%

Vulnerability Summary

CVE-2026-3099: 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.

Impacted Vendors

libsoup 1

gnome 1

Reference Links

https://access.redhat.com/security/cve/CVE-2026-3099 https://bugzilla.redhat.com/show_bug.cgi?id=2442232

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

5.8

Attack Vector

NETWORK

Complexity

HIGH

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L

CVSS v3.1

Source Entity [email protected]

Severity HIGH

7.3

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

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

Associated Attack Patterns (CAPEC)

Total: Patterns