Use-After-Free Flaw in libsoup for HTTP/2 Server Implementation
CVE-2026-4271

5.3MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 10.0 Extended Update Support
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Vendor
CVE Published:
17 March 2026

What is CVE-2026-4271?

An identified flaw in libsoup, a crucial library for managing HTTP requests, encompasses a Use-After-Free vulnerability within its HTTP/2 server functionality. This security weakness allows remote attackers to transmit specially crafted HTTP/2 requests to manipulate authentication processes, resulting in the potential access of previously freed memory. Such behavior may lead to application disruptions and crashes, thereby causing Denial of Service (DoS) conditions, which could impair essential services relying on this library.

Affected Version(s)

Red Hat Enterprise Linux 10 0:3.6.5-3.el10_1.11

Red Hat Enterprise Linux 10 0:3.6.5-3.el10_2.11

Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.6.5-3.el10_0.15

References

https://access.redhat.com/errata/RHSA-2026:15968
vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:17482
vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:19143
vendor-advisoryx_refsource_REDHAT

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank fouzhe for reporting this issue.
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