CVE-2026-4271
This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.83% probability · 55th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- gnome/libsoup · redhat/enterprise linux
- Source
- secalert@redhat.com
References
- https://access.redhat.com/errata/RHSA-2026:15968
- https://access.redhat.com/errata/RHSA-2026:17482
- https://access.redhat.com/errata/RHSA-2026:19143
- https://access.redhat.com/security/cve/CVE-2026-4271Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2448044Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/496Exploit, Issue Tracking, Vendor Advisory
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/496Exploit, Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.