CVE & CISA-KEV CatalogNVD
CVE-2026-4271
MEDIUM5.3
CVSS v3
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).
How to fix
Remediation Available
libsoup3Red Hat / RHEL
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
libsoup3Rocky
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
libsoup3-debuginfoRocky
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
libsoup3-debuginfoRed Hat / RHEL
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
libsoup3-debugsourceRocky
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
libsoup3-debugsourceRed Hat / RHEL
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
libsoup3-develRed Hat / RHEL
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
libsoup3-develRocky
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
libsoup3-docRocky
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
libsoup3-docRed Hat / RHEL
Fixed in:0:3.6.5-3.el10_2.11RHSA-2026:19143
Fixed in:0:3.6.5-3.el10_0.15RHSA-2026:17482
Fixed in:0:3.6.5-3.el10_1.11RHSA-2026:15968
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Exploit Intelligence
0.83%probability of exploitation in 30 days
53rdpercentile
Moderate risk: more likely to be exploited than 53% of all known CVEs.
References
Exploit1
Vendor Advisory2
Other references3
Related Vulnerabilities
Other CWE-416 (Use After Free) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2019-0708 | Critical | 9.8 | 100% | KEV + Ransom | - |
| CVE-2021-31166 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2015-5119 | Critical | 9.8 | 99% | KEV | - |
| CVE-2010-3962 | High | 8.1 | 97% | KEV | - |
| CVE-2015-0313 | Critical | 9.8 | 96% | KEV | Fix |
| CVE-2017-9798 | High | 7.5 | 95% | - | Fix |
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Markdown
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-19.