- 5.3MediumCVSS base score
- 0.88%Exploitation in 30 daysEPSS · top 40% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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).
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
Timeline
ID reserved
By redhat
- 1 day later
· 1 day later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.88% · top 40% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Red Hat · Red Hat Enterprise Linux 10
- unaffected 0:3.6.5-3.el10_1.11 – < *
Red Hat · Red Hat Enterprise Linux 10
- unaffected 0:3.6.5-3.el10_2.11 – < *
Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support
- unaffected 0:3.6.5-3.el10_0.15 – < *
Red Hat · Red Hat Enterprise Linux 6
All versions: affected
Red Hat · Red Hat Enterprise Linux 7
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 8
All versions: unaffected
Red Hat · Red Hat Enterprise Linux 9
All versions: unaffected
What to do
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.
References
References6
- RHSA-2026:15968 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:17482 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:19143 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-4271 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2448044 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/496 (opens in a new tab)exploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-12568 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-4271)Record last updated .