CVE-2026-4271 (GCVE-0-2026-4271)
Vulnerability from cvelistv5 – Published: 2026-03-17 11:14 – Updated: 2026-05-19 21:30
VLAI
EPSS
VEX
Title
Libsoup: libsoup: denial of service via use-after-free in http/2 server
Summary
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).
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-17 13:04 UTC
CWE
- CWE-416 - Use After Free
Assigner
References
6 references
| URL | Tags |
|---|---|
| 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 |
| https://access.redhat.com/security/cve/CVE-2026-4271 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2448044 | issue-trackingx_refsource_REDHAT |
| https://gitlab.gnome.org/GNOME/libsoup/-/issues/496 |
Impacted products
7 products
| Vendor | Product | Version | |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 |
Unaffected:
0:3.6.5-3.el10_1.11 , < *
(rpm)
cpe:/o:redhat:enterprise_linux:10.1 |
|
| Red Hat | Red Hat Enterprise Linux 10 |
Unaffected:
0:3.6.5-3.el10_2.11 , < *
(rpm)
cpe:/o:redhat:enterprise_linux:10.2 |
|
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support |
Unaffected:
0:3.6.5-3.el10_0.15 , < *
(rpm)
cpe:/o:redhat:enterprise_linux_eus:10.0 |
|
| Red Hat | Red Hat Enterprise Linux 6 |
cpe:/o:redhat:enterprise_linux:6
|
|
| Red Hat | Red Hat Enterprise Linux 7 |
cpe:/o:redhat:enterprise_linux:7
|
|
| Red Hat | Red Hat Enterprise Linux 8 |
cpe:/o:redhat:enterprise_linux:8
|
|
| Red Hat | Red Hat Enterprise Linux 9 |
cpe:/o:redhat:enterprise_linux:9
|
Date Public
2026-03-16 00:00
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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