CVE-2025-4476
Description
A denial-of-service vulnerability has been identified in the libsoup HTTP client library. This flaw can be triggered when a libsoup client receives a 401 (Unauthorized) HTTP response containing a specifically crafted domain parameter within the WWW-Authenticate header. Processing this malformed header can lead to a crash of the client application using libsoup. An attacker could exploit this by setting up a malicious HTTP server. If a user's application using the vulnerable libsoup library connects to this malicious server, it could result in a denial-of-service. Successful exploitation requires tricking a user's client application into connecting to the attacker's malicious server.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | affected | |
| debian | bullseye | fixed | 2.72.0-2+deb11u3 |
| debian | trixie | fixed | 3.6.5-2 |
| debian | forky | fixed | 3.6.5-2 |
| debian | sid | fixed | 3.6.5-2 |
| sles | affected | |
References
- https://access.redhat.com/security/cve/CVE-2025-4476
- https://bugzilla.redhat.com/show_bug.cgi?id=2366513
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/440
- https://gitlab.gnome.org/GNOME/libsoup/-/work_items/440
- https://security-tracker.debian.org/tracker/CVE-2025-4476
- https://www.suse.com/security/cve/CVE-2025-4476.html
CWEs
CWE-476
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.