{"id":"CVE-2026-15711","title":"A vulnerability was found in libsoup's WebSocket frame parsing implementation","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 pa…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-770"],"vendor":"Red Hat","product":"libsoup3","affected":["libsoup3 (all versions)","libsoup (all versions)","libsoup (all versions)","libsoup (all versions)","libsoup (all versions)","libsoup (all versions)","libsoup","libsoup"],"patched":["enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_8","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_8","enterprise_linux_codeready_linux_builder_v_10"],"published":"2026-07-14","updated":"2026-09-21","sourceUpdated":"2026-09-21T15:17:28.020","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-15711","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:68234","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:68235","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:68266","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:68612","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:69108","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:69297","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-15711","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2499924","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515","label":"secalert@redhat.com"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/issues/515","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-15711.json"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-15711"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15711"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"epss":0.00482,"epssPercentile":0.40559,"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-07-15T14:10:43.407984Z"},"ingestedAt":"2026-09-16T19:02:30.738Z","slug":"CVE-2026-15711","body":"## Overview\n\nA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:68235** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68235)\n- **RHSA-2026:68266** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68266)\n- **RHSA-2026:68234** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68234)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-15711.json)\n- **RHSA-2026:68612** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68612)\n- **RHSA-2026:69297** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69297)\n- **RHSA-2026:69108** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69108)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}