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.
Problem types
Reusing a Nonce, Key Pair in Encryption
Product status
Timeline
| 2026-02-24: | Reported to Red Hat. |
| 2026-02-24: | Made public. |
Credits
Red Hat would like to thank Cavid for reporting this issue.
References
access.redhat.com/security/cve/CVE-2026-3099
bugzilla.redhat.com/show_bug.cgi?id=2442232 (RHBZ#2442232)
gitlab.gnome.org/GNOME/libsoup/-/issues/495