Vulnerability · Published Dec 11, 2025 · Assigned by redhat
CVE-2025-14523Libsoup: libsoup: duplicate host header handling causes host-parsing discrepancy (first- vs last-value wins)
High 8.2
In plain English
A high-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 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | libsoup | 2.62.3-11.el8_10 | ALSA-2026:0421 |
| AlmaLinux:9 | libsoup | 2.72.0-12.el9_7.3 | ALSA-2026:0422 |
| AlmaLinux:8 | libsoup-devel | 2.62.3-11.el8_10 | ALSA-2026:0421 |
| AlmaLinux:9 | libsoup-devel | 2.72.0-12.el9_7.3 | ALSA-2026:0422 |
| AlmaLinux:10 | libsoup3-doc | 3.6.5-3.el10_1.8 | ALSA-2026:0423 |
| Debian:12 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-14523 |
| Debian:13 | libsoup2.4 | no fix listed | DEBIAN-CVE-2025-14523 |
| Debian:12 | libsoup3 | no fix listed | DEBIAN-CVE-2025-14523 |
| Debian:13 | libsoup3 | no fix listed | DEBIAN-CVE-2025-14523 |
| Rocky Linux:8 | libsoup | 0:2.62.3-11.el8_10 | RLSA-2026:0421 |
| Rocky Linux:9 | libsoup | 0:2.72.0-12.el9_7.3 | RLSA-2026:0422 |
| Rocky Linux:10 | libsoup3 | 0:3.6.5-3.el10_1.8 | RLSA-2026:0423 |
| Rocky Linux:8 | spice-client-win | 0:8.10-6.el8_10.1 | RLSA-2026:1509 |
| Ubuntu:22.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-14523 |
| Ubuntu:24.04:LTS | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-14523 |
| Ubuntu:25.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-14523 |
| Ubuntu:26.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2025-14523 |
| Ubuntu:24.04:LTS | libsoup3 | no fix listed | UBUNTU-CVE-2025-14523 |
| Ubuntu:25.10 | libsoup3 | no fix listed | UBUNTU-CVE-2025-14523 |
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
References
- RHSA-2026:0421 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0422 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0423 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0836 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0867 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0868 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0905 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0906 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0907 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0908 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0909 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0911 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0925 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:1509 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:1569 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:1570 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:1571 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:1572 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2025-14523 vdb-entry, x_refsource_REDHAT
- RHBZ#2421349 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/472