{"id":"CVE-2026-87724","title":"Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state","summary":"Tor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","cwe":["CWE-669"],"vendor":"torprject","product":"Tor","affected":["Tor >= 0.4.9.3-alpha < 0.4.9.12"],"published":"2026-09-09","updated":"2026-09-09","sourceUpdated":"2026-09-09T19:17:50.287","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-87724","references":[{"url":"https://gitlab.com/torproject/tor/-/commit/10d4b8ffefa7c00aab2b631ed7e7f15e42cd012d","label":"cve@mitre.org"},{"url":"https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.12/ChangeLog","label":"cve@mitre.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-87724.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-87724"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-87724"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-09T18:18:26.862750Z"},"epss":0.0026,"epssPercentile":0.17998,"ingestedAt":"2026-09-09T02:19:39.649Z","slug":"CVE-2026-87724","body":"## Overview\n\nTor before 0.4.9.12 interprets the CC_RESPONSE extension even when CC_REQUEST was not sent, which allows remote attackers to cause a denial of service (crash) because of corrupted congestion-control state. This is TROVE-2026-032.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-87724.json)","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}