synced JUST NOW
01 Record

CVE-2026-4271

Libsoup: libsoup: denial of service via use-after-free in http/2 server

MediumPUBLISHEDCNA: redhat
CNA base score5.3 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

02 Description

Libsoup: libsoup: denial of service via use-after-free in http/2 server

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.86% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 58.1% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-03-17 11:14Z7 MO AGO
Last updated
2026-05-19 21:30Z5 MO AGO
Reserved
2026-03-16
Assigning CNA
redhat
Record state
PUBLISHED
Severity
Medium (CVSS 5.3)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weaknesses
Data version
5.2
Document digest
0dd9caaa1a3655b9b0f7bede748ede4bfe26add7a571c9fd37d450e035ed45fa

05 Affected products

VendorProductVersionsPlatforms
Red HatRed Hat Enterprise Linux 10Not specified—
Red HatRed Hat Enterprise Linux 6Not specified—
Red HatRed Hat Enterprise Linux 7Not specified—
Red HatRed Hat Enterprise Linux 8Not specified—
Red HatRed Hat Enterprise Linux 9Not specified—

06 References

07 Fixed in

AlmaLinux 10

  • libsoup3
    Fixed in 3.6.5-3.el10_2.11
  • libsoup3-devel
    Fixed in 3.6.5-3.el10_2.11
  • libsoup3-doc
    Fixed

    A version is affected if any line below covers it.

    • Affected before 3.6.5-3.el10_1.11
    • Affected before 3.6.5-3.el10_2.11

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 10

  • libsoup3
    Fixed in 3.6.5-3.el10_2.11
  • libsoup3-devel
    Fixed in 3.6.5-3.el10_2.11
  • libsoup3-doc
    Fixed

    A version is affected if any line below covers it.

    • Affected before 3.6.5-3.el10_1.11
    • Affected before 3.6.5-3.el10_2.11

Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • libsoup2.4
    No fix yet
  • libsoup3
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • libsoup2.4
    No fix yet
  • libsoup3
    No fix yet

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • libsoup3
    Fixed in 3.8.0-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • libsoup3
    Fixed in 3.4.4-5ubuntu0.9

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • libsoup3
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • libsoup3
    Fixed in 3.6.6-1ubuntu0.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.10

  • libsoup3
    Fixed in 3.6.6-1ubuntu3

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.