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  4. CVE 2026 4271 libsoup libsoup denial of service via use after
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Back to active CVEs
Medium · CVSS 5.3CVE-2026-4271

Libsoup: libsoup: denial of service via use-after-free in http/2 serverCVE-2026-4271

Answer in brief

CVE-2026-4271 records a Medium severity (CVSS 5.3) vulnerability in Libsoup: libsoup: denial of service via use-after-free in http/2 server. The current sources do not mark it as known exploited. The current feed maps Red Hat/libsoup (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Mar 17, 2026Updated Nov 5, 2026Source checked Nov 5, 2026First seen by HOL Nov 5, 2026Material review Nov 5, 2026
Upstream Advisory

Key facts

Risk
Medium · CVSS 5.3
Exploitation
Not marked as known exploited
Affected software
7 mapped packages or products
Fix availability
Not reported

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Red Hat/libsoup (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
ProductAffected versionsFixed versions
cpe:2.3:a:gnome:libsoup:-:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*Not reportedNot reported
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*Not reportedNot reported
Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Red Hat/libsoupgeneric*Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Red Hat/libsoup.
  2. 2Review the reported fix. Source-reported workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Evidence timeline and material changes

  1. Published upstream

    Mar 17, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Nov 5, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Nov 5, 2026

Sources and claim methodology

  • Source referenceaccess.redhat.com
  • Source referenceaccess.redhat.com
  • Source referenceaccess.redhat.com
  • Source referenceaccess.redhat.com
  • Source referencebugzilla.redhat.com
  • Source referencegitlab.gnome.org
Upstream source 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).

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • FastNetMon: NetFlow/IPFIX template cache returns unlocked pointers, causing heap-use-after-free on multi-port deploymentsAlso CWE-416

Record context

Vulnerability class
Memory Corruption
EPSS
Not reported
CWE IDs
CWE-416
Source
CVE List V5
Source checked
Nov 5, 2026
References
6 linked sources
Open source record