Vulnerability · Published Jul 21, 2026 · Assigned by redhat
CVE-2026-12548Libsoup: heap out-of-bounds read in libsoup due to integer truncation
Medium 4.2
In plain English
A medium-severity out-of-bounds read in Red Hat Enterprise Linux 10 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A heap out-of-bounds read flaw was found in libsoup. When parsing multipart HTTP messages, an integer type mismatch between the caller and soup_headers_parse() can cause the length parameter to be incorrectly truncated, leading to a heap buffer over-read. A remote attacker could use this flaw to crash an application using libsoup or potentially disclose heap memory contents.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libsoup2.4 | no fix listed | DEBIAN-CVE-2026-12548 |
| Debian:13 | libsoup2.4 | no fix listed | DEBIAN-CVE-2026-12548 |
| Debian:12 | libsoup3 | no fix listed | DEBIAN-CVE-2026-12548 |
| Debian:13 | libsoup3 | no fix listed | DEBIAN-CVE-2026-12548 |
| Ubuntu:22.04:LTS | libsoup2.4 | 2.74.2-3ubuntu0.10 | USN-8975-1 |
| Ubuntu:22.04:LTS | libsoup2.4 | 2.74.2-3ubuntu0.10 | UBUNTU-CVE-2026-12548 |
| Ubuntu:24.04:LTS | libsoup2.4 | 2.74.3-6ubuntu1.10 | USN-8975-1 |
| Ubuntu:24.04:LTS | libsoup2.4 | 2.74.3-6ubuntu1.10 | UBUNTU-CVE-2026-12548 |
| Ubuntu:26.10 | libsoup2.4 | no fix listed | UBUNTU-CVE-2026-12548 |
| Ubuntu:24.04:LTS | libsoup3 | 3.4.4-5ubuntu0.10 | UBUNTU-CVE-2026-12548 |
| Ubuntu:24.04:LTS | libsoup3 | 3.4.4-5ubuntu0.10 | USN-8975-1 |
| Ubuntu:26.04:LTS | libsoup3 | 3.6.6-1ubuntu0.2 | USN-8975-1 |
| Ubuntu:26.04:LTS | libsoup3 | 3.6.6-1ubuntu0.2 | UBUNTU-CVE-2026-12548 |
| Ubuntu:26.10 | libsoup3 | 3.6.6-1ubuntu3.1 | UBUNTU-CVE-2026-12548 |
| Ubuntu:26.10 | libsoup3 | 3.6.6-1ubuntu3.1 | USN-8975-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L
References
- https://access.redhat.com/security/cve/CVE-2026-12548 vdb-entry, x_refsource_REDHAT
- RHBZ#2489996 issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/work_items/512