Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-15711
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-14 20:16:57 UTC
Updated2026-07-15 18:20:21 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.004310000 probability, percentile 0.348990000 (date 2026-07-19)

Problem Types: CWE-770 | CWE-770 Allocation of Resources Without Limits or Throttling

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Red Hat Red Hat Enterprise Linux 10 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 6 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 7 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 8 Not specified Not specified
CNA Red Hat Red Hat Enterprise Linux 9 Not specified Not specified

References

ReferenceSourceLinkTags
bugzilla.redhat.com/show_bug.cgi [email protected] bugzilla.redhat.com
gitlab.gnome.org/GNOME/libsoup/-/issues/515 134c704f-9b21-4f2e-91b3-4a467353bcc0 gitlab.gnome.org
access.redhat.com/security/cve/CVE-2026-15711 [email protected] access.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Red Hat would like to thank Sebastián Alba Vives (@Sebasteuo / 0xS4bb1) for reporting this issue. (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-07-14T09:46:13.021ZReported to Red Hat.
CNA2026-07-14T09:52:00.000ZMade public.

Workarounds

CNA: 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.

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