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).
Affected products
gnome: libsoup; redhat: enterprise linux
References7
- access.redhat.com/security/cve/CVE-2026-4271 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2448044 Issue TrackingVendor Advisory
- gitlab.gnome.org/GNOME/libsoup/-/issues/496 ExploitIssue TrackingVendor Advisory
- gitlab.gnome.org/GNOME/libsoup/-/issues/496 ExploitIssue TrackingVendor Advisory
- access.redhat.com/errata/RHSA-2026:15968
- access.redhat.com/errata/RHSA-2026:17482
- access.redhat.com/errata/RHSA-2026:19143
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 61 · as of 12 November 2026
- CWE
- CWE-416
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.