CVE-2026-15711
Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation
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.
Fixes and workarounds
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Enterprise Linux 10 Red Hat libsoup3
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:3.6.5-3.el10_2.14; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 10.0 Extended Update Support Red Hat libsoup3
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:3.6.5-3.el10_0.17; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8 Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-15.el8_10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-2.el8_4.10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-2.el8_4.10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-2.el8_6.10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-2.el8_6.10; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-3.el8_8.11; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.62.3-3.el8_8.11; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.72.0-16.el9_8.3; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.72.0-8.el9_2.13; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.72.0-8.el9_4.12; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9.6 Extended Update Support Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
≥ 0:2.72.0-10.el9_6.9; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 6 Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unknown |
CNA: redhat |
| Red Hat Enterprise Linux 7 Red Hat libsoup
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unknown |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA: redhat |
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD: [email protected] |
Exploit evidence
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/515
exploit · ADP: CISA-ADP
References
- https://access.redhat.com/errata/RHSA-2026:68234CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:68235CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:68266CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:68612CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:69108CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:69297CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:69863CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:70598CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:70599CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:71389CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-15711CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2499924CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/515CNA: redhat
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/515ADP: CISA-ADP · exploit
- https://access.redhat.com/errata/RHSA-2026:68234[email protected]
- https://access.redhat.com/errata/RHSA-2026:68235[email protected]
- https://access.redhat.com/errata/RHSA-2026:68266[email protected]
- https://access.redhat.com/errata/RHSA-2026:68612[email protected]
- https://access.redhat.com/errata/RHSA-2026:69108[email protected]
- https://access.redhat.com/errata/RHSA-2026:69297[email protected]
- https://access.redhat.com/errata/RHSA-2026:69863[email protected]
- https://access.redhat.com/errata/RHSA-2026:70598[email protected]
- https://access.redhat.com/errata/RHSA-2026:70599[email protected]
- https://access.redhat.com/errata/RHSA-2026:71389[email protected]
- https://access.redhat.com/security/cve/CVE-2026-15711[email protected]
- https://bugzilla.redhat.com/show_bug.cgi?id=2499924[email protected]
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/515[email protected]
- https://gitlab.gnome.org/GNOME/libsoup/-/issues/515134c704f-9b21-4f2e-91b3-4a467353bcc0
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