{"id":"CVE-2026-12549","title":"Libsoup: incomplete fix for cve-2026-2443: range suffix overflow in libsoup soupserver","summary":"The fix for CVE-2026-2443 was regressed by a subsequent rework commit that replaced specific overflow checks with a general signed comparison. When a client sends a Range request with a suffix length exceeding the content size, the resul…","severity":"medium","cvss":4.8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L","cvssSource":"cna","cwe":["CWE-805"],"vendor":"Red Hat","product":"libsoup3","affected":["libsoup3 (all versions)","libsoup","libsoup","libsoup (all versions)","libsoup (all versions)"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-06-23T14:05:45.451175Z"},"published":"2026-06-22","updated":"2026-11-05","sourceUpdated":"2026-11-05T17:02:49.097Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-12549","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-12549"},{"url":"https://access.redhat.com/security/cve/cve-2026-0716","label":"cve-2026-0716"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2489999","label":"RHBZ#2489999"},{"url":"https://gitlab.gnome.org/GNOME/libsoup/-/work_items/516"}],"tags":["cve.org"],"epss":0.00357,"epssPercentile":0.29546,"ingestedAt":"2026-11-05T22:38:31.416Z","slug":"CVE-2026-12549","body":"## Overview\n\nThe fix for CVE-2026-2443 was regressed by a subsequent rework commit that replaced specific overflow checks with a general signed comparison. When a client sends a Range request with a suffix length exceeding the content size, the resulting negative start value is not properly clamped, leading to malformed HTTP 206 responses and log flooding.\n\n## Affected\n\n- `libsoup3 (all versions)`\n- `libsoup`\n- `libsoup`\n- `libsoup (all versions)`\n- `libsoup (all versions)`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nTo mitigate this issue, applications utilizing libsoup's WebSocket support should ensure that the `max_incoming_payload_size` is explicitly set to a non-zero value. This prevents the library from processing WebSocket frames with an unset or zero maximum payload size, which can lead to out-of-bounds reads. Consult application-specific documentation for configuring libsoup parameters.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":26.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}