Vulnerability · Published Sep 3, 2025 · Assigned by redhat
CVE-2025-9901Libsoup: improper handling of http vary header in libsoup caching
Medium 5.9
In plain English
A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities).
Official description
A flaw was found in libsoup’s caching mechanism, SoupCache, where the HTTP Vary header is ignored when evaluating cached responses. This header ensures that responses vary appropriately based on request headers such as language or authentication. Without this check, cached content can be incorrectly reused across different requests, potentially exposing sensitive user information. While the issue is unlikely to affect everyday desktop use, it could result in confidentiality breaches in proxy or multi-user environments.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | libsoup | no fix listed | DEBIAN-CVE-2025-9901 |
| Debian:12 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-9901 |
| Debian:13 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-9901 |
| Debian:12 | libsoup3 | no fix listed | DEBIAN-CVE-2025-9901 |
| Debian:13 | libsoup3 | no fix listed | DEBIAN-CVE-2025-9901 |
| Ubuntu:22.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:24.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:25.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:26.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:24.04:LTS | libsoup3 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:25.10 | libsoup3 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:26.04:LTS | libsoup3 | no fix listed | UBUNTU-CVE-2025-9901 |
| Ubuntu:26.10 | libsoup3 | no fix listed | UBUNTU-CVE-2025-9901 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
Weakness: CWE-524 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://access.redhat.com/security/cve/CVE-2025-9901 vdb-entry, x_refsource_REDHAT
- RHBZ#2392790 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/453