{"id":"CVE-2026-77640","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77640","generatedAt":"2026-10-28T02:15:09.149Z","title":"tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip stream with done=1.","description":"tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip  stream with done=1. A truncated stream never reaches Z_STREAM_END,  causing zlib to return Z_BUF_ERROR with no input remaining, which  buf_add_compress() mistook for a full output buffer and retried forever. Fixed by returning TOR_COMPRESS_ERROR in that case so the caller can abort cleanly. This is TROVE-2026-021.","published":"2026-08-20T21:17:11.000Z","lastModified":"2026-10-18T20:10:00.000Z","status":"Analyzed","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"cwe":["CWE-1284"],"affected":["torproject/tor"],"epss":{"score":0.00378,"percentile":0.3152,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.38%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog","tags":["Permissions Required","Release Notes","Vendor Advisory"],"source":"cve@mitre.org"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77640","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}