CVE-2026-15711 json
Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation
published 2026-07-14 3 mo ago modified 2026-11-05 3 d ago also EUVD-2026-44428
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
A vulnerability was found in libsoup's WebSocket frame parsing implementation. The library fails to validate length rules specified in RFC 6455 §5.5, which mandates that all WebSocket control frames (e.g., PING, PONG, CLOSE) contain a payload of 125 bytes or less. A remote, unauthenticated attacker can exploit this by sending a non-compliant, oversized control frame. Because the parser handles this protocol violation improperly instead of throwing an immediate connection termination error, it triggers a internal processing crash, resulting in a remote denial of service (DoS) for applications utilizing libsoup WebSockets.
Patch / fix
- Red Hat Red Hat Enterprise Linux 10 0:3.6.5-3.el10_2.14
- Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.6.5-3.el10_0.17
- Red Hat Red Hat Enterprise Linux 8 0:2.62.3-15.el8_10
- Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:2.62.3-2.el8_4.10
- Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:2.62.3-2.el8_4.10
- Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.62.3-2.el8_6.10
- Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:2.62.3-2.el8_6.10
- Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:2.62.3-3.el8_8.11
- Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:2.62.3-3.el8_8.11
- Red Hat Red Hat Enterprise Linux 9 0:2.72.0-16.el9_8.3
- Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:2.72.0-8.el9_2.13
- Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:2.72.0-8.el9_4.12
- Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:2.72.0-10.el9_6.9
- libsoup3 RHEL 10.2 3.6.5-3.el10_2.14
- libsoup RHEL 8 2.62.3-15.el8_10
- libsoup RHEL 9 2.72.0-16.el9_8.3
- libsoup3 enterprise linux eus 10.0 3.6.5-3.el10_0.17
- libsoup RHEL 8.4 EUS_LONG_LIFE, RHEL 8.4 AUS 2.62.3-2.el8_4.10
- libsoup RHEL 8.6 EUS_LONG_LIFE, RHEL 8.6 AUS 2.62.3-2.el8_6.10
- libsoup RHEL 8.8 TUS, RHEL 8.8 E4S 2.62.3-3.el8_8.11
- libsoup RHEL 9.2 E4S 2.72.0-8.el9_2.13
red hat advisories RHSA-2026:71389RHSA-2026:70599RHSA-2026:70598RHSA-2026:69863RHSA-2026:69297RHSA-2026:69108
- libsoup SLES for SAP applications 16.0, SLES 16.0 3.6.6-160000.5.1
- libsoup Linux Micro 6.0 3.4.2-159998.1.1
- libsoup2 SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +8 more 2.74.3-150400.3.43.1
- libsoup2 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 2.74.3-150600.4.42.1
- libsoup SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 3.4.4-150600.3.56.1
- libsoup SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 3.0.4-150400.3.52.1
- libsoup SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.62.2-5.49.1
suse advisories SUSE-SU-2026:24470-1SUSE-SU-2026:24368-1SUSE-SU-2026:4739-1SUSE-SU-2026:4703-1SUSE-SU-2026:4690-1SUSE-SU-2026:4558-1
- libsoup openSUSE Tumbleweed 3.8.1-1.1
- libsoup openSUSE Leap 16.0 3.6.6-160000.5.1
- libsoup2 openSUSE Tumbleweed 2.74.3-24.1
opensuse advisories openSUSE-SU-2026:12365-1openSUSE-SU-2026:22181-1openSUSE-SU-2026:12084-1
- libsoup AlmaLinux 9 2.72.0-16.el9_8.3
- libsoup3 AlmaLinux 10 3.6.5-3.el10_2.14
- libsoup AlmaLinux 8 2.62.3-15.el8_10
almalinux advisories ALSA-2026:68234ALSA-2026:68235ALSA-2026:68266
- libsoup Rocky Linux 8 2.62.3-15.el8_10
- libsoup Rocky Linux 9 2.72.0-16.el9_8.3
rocky linux advisories RLSA-2026:68266RLSA-2026:68234
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-15711 updated cvss 7.5
libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control frame protocol violation
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Red Hat Enterprise Linux 6 libsoup Red Hat Enterprise Linux 7 libsoupaffected: workaround, no fix planned “Out of support scope”
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Red Hat Enterprise Linux AppStream (v. 8) libsoup-devel 2.62.3-15.el8_10, libsoup-debuginfo 2.62.3-15.el8_10, libsoup-debugsource 2.62.3-15.el8_10fixed: vendor fix RHSA-2026:68266
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Red Hat Enterprise Linux AppStream (v. 9) libsoup 2.72.0-16.el9_8.3fixed: vendor fix RHSA-2026:68234
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Red Hat Enterprise Linux AppStream (v. 10) libsoup3 3.6.5-3.el10_2.14fixed: vendor fix RHSA-2026:68235
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Red Hat Enterprise Linux AppStream AUS (v.8.4) libsoup-devel 2.62.3-2.el8_4.10, libsoup-debuginfo 2.62.3-2.el8_4.10, libsoup-debugsource 2.62.3-2.el8_4.10fixed: vendor fix RHSA-2026:70599
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Red Hat Enterprise Linux AppStream AUS (v.8.6) libsoup-devel 2.62.3-2.el8_6.10, libsoup-debuginfo 2.62.3-2.el8_6.10, libsoup-debugsource 2.62.3-2.el8_6.10fixed: vendor fix RHSA-2026:70598
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Red Hat Enterprise Linux AppStream E4S (v.8.8) libsoup-devel 2.62.3-3.el8_8.11, libsoup-debuginfo 2.62.3-3.el8_8.11, libsoup-debugsource 2.62.3-3.el8_8.11fixed: vendor fix RHSA-2026:69863
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Red Hat Enterprise Linux AppStream E4S (v.9.2) libsoup 2.72.0-8.el9_2.13fixed: vendor fix RHSA-2026:69297
show 15 moreshow fewer
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Red Hat Enterprise Linux AppStream E4S (v.9.4) libsoup 2.72.0-8.el9_4.12fixed: vendor fix RHSA-2026:69108
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Red Hat Enterprise Linux AppStream EUS (v. 10.0) libsoup3 3.6.5-3.el10_0.17fixed: vendor fix RHSA-2026:71389
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Red Hat Enterprise Linux AppStream EUS (v.9.6) libsoup 2.72.0-10.el9_6.9fixed: vendor fix RHSA-2026:68612
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Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libsoup-devel 2.62.3-2.el8_4.10, libsoup-debuginfo 2.62.3-2.el8_4.10, libsoup-debugsource 2.62.3-2.el8_4.10fixed: vendor fix RHSA-2026:70599
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Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libsoup-devel 2.62.3-2.el8_6.10, libsoup-debuginfo 2.62.3-2.el8_6.10, libsoup-debugsource 2.62.3-2.el8_6.10fixed: vendor fix RHSA-2026:70598
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Red Hat Enterprise Linux AppStream TUS (v.8.8) libsoup-devel 2.62.3-3.el8_8.11, libsoup-debuginfo 2.62.3-3.el8_8.11, libsoup-debugsource 2.62.3-3.el8_8.11fixed: vendor fix RHSA-2026:69863
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Red Hat Enterprise Linux BaseOS (v. 8) libsoup 2.62.3-15.el8_10fixed: vendor fix RHSA-2026:68266
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Red Hat Enterprise Linux BaseOS AUS (v.8.4) libsoup 2.62.3-2.el8_4.10fixed: vendor fix RHSA-2026:70599
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Red Hat Enterprise Linux BaseOS AUS (v.8.6) libsoup 2.62.3-2.el8_6.10fixed: vendor fix RHSA-2026:70598
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Red Hat Enterprise Linux BaseOS E4S (v.8.8) libsoup 2.62.3-3.el8_8.11fixed: vendor fix RHSA-2026:69863
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Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) libsoup 2.62.3-2.el8_4.10fixed: vendor fix RHSA-2026:70599
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Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) libsoup 2.62.3-2.el8_6.10fixed: vendor fix RHSA-2026:70598
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Red Hat Enterprise Linux BaseOS TUS (v.8.8) libsoup 2.62.3-3.el8_8.11fixed: vendor fix RHSA-2026:69863
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Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libsoup3-doc 3.6.5-3.el10_2.14fixed: vendor fix RHSA-2026:68235
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Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libsoup3-doc 3.6.5-3.el10_0.17fixed: vendor fix RHSA-2026:71389
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 3 mo ago
Exploit prediction
0.74% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- gitlab.gnome.org https://gitlab.gnome.org/GNOME/libsoup/-/issues/515 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
- Red Hat Red Hat Enterprise Linux 10
- Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
- Red Hat Red Hat Enterprise Linux 8
- Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
- Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
- Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
- Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
- Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
- Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
- Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
- Red Hat Red Hat Enterprise Linux 6
- Red Hat Red Hat Enterprise Linux 7
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
gitlab.gnome.org
/GNOME/libsoup/-/issues/515
exploit
-
access.redhat.com
/errata/RHSA-2026:68234
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:68235
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:68266
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:68612
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:69108
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:69297
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:69863
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:70598
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:70599
vendor-advisory
-
access.redhat.com
/errata/RHSA-2026:71389
vendor-advisory
-
access.redhat.com
/security/cve/CVE-2026-15711
vdb-entry
-
bugzilla.redhat.com
/show_bug.cgi?id=2499924
issue-tracking
Sources
- CVE List CVE-2026-15711
- NVD CVE-2026-15711
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.