High severity · published Jul 14, 2026
CVE-2026-15711
Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation
7.5
CVSS
0.7%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 55% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.8 Telecommunications Update Service · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-15711
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-15711
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:68234
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:68235
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:68266
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:68612
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:69108
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:69297
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