CVE-2026-4271

Name: CVE-2026-4271
Creator: NVD / NIST
Published: 2026-03-17T12:16:13.28+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.83%

Last modified Jun 17, 2026

CVE-2026-4271 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.83% chance of exploitation in the next 30 days.

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).

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.83%

52.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Gnome	Libsoup	All versions
Redhat	Enterprise Linux	6.0
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Redhat	Enterprise Linux	9.0
Redhat	Enterprise Linux	10.0

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

Timeline

Published: Mar 17, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-4271?

How severe is CVE-2026-4271?

CVE-2026-4271 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.83% probability of exploitation in the next 30 days.

How do I fix CVE-2026-4271?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-4271?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST