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Vulnerability · Published Jul 14, 2026 · Assigned by redhat

CVE-2026-15711Libsoup: soupwebsocketconnection: libsoup: websocket remote denial of service via oversized control frame protocol violation

High 7.5

In plain English

A high-severity resource allocation without limits in Red Hat Enterprise Linux 10 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 45.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8libsoup2.62.3-15.el8_10ALSA-2026:68266
AlmaLinux:9libsoup2.72.0-16.el9_8.3ALSA-2026:68234
AlmaLinux:8libsoup-devel2.62.3-15.el8_10ALSA-2026:68266
AlmaLinux:9libsoup-devel2.72.0-16.el9_8.3ALSA-2026:68234
AlmaLinux:10libsoup33.6.5-3.el10_2.14ALSA-2026:68235
AlmaLinux:10libsoup3-devel3.6.5-3.el10_2.14ALSA-2026:68235
AlmaLinux:10libsoup3-doc3.6.5-3.el10_2.14ALSA-2026:68235
Debian:12libsoup2.4no fix listedDEBIAN-CVE-2026-15711
Debian:13libsoup2.4no fix listedDEBIAN-CVE-2026-15711
Debian:12libsoup3no fix listedDEBIAN-CVE-2026-15711
Debian:13libsoup3no fix listedDEBIAN-CVE-2026-15711
Rocky Linux:8libsoup0:2.62.3-15.el8_10RLSA-2026:68266
Rocky Linux:9libsoup0:2.72.0-16.el9_8.3RLSA-2026:68234
Ubuntu:22.04:LTSlibsoup2.4no fix listedUBUNTU-CVE-2026-15711
Ubuntu:24.04:LTSlibsoup2.4no fix listedUBUNTU-CVE-2026-15711
Ubuntu:26.10libsoup2.4no fix listedUBUNTU-CVE-2026-15711
Ubuntu:24.04:LTSlibsoup3no fix listedUBUNTU-CVE-2026-15711
Ubuntu:26.04:LTSlibsoup3no fix listedUBUNTU-CVE-2026-15711
Ubuntu:26.10libsoup3no fix listedUBUNTU-CVE-2026-15711

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support see references
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On see references
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support see references
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On see references
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service see references
Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References