{"id":"CVE-2026-77640","state":"PUBLISHED","title":"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 retur","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.","publishedAt":"2026-08-20T21:02:36.470Z","updatedAt":"2026-08-21T20:08:38.526Z","severity":{"score":3.7,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"mitre"},"assigner":"mitre","products":["torproject Tor"],"affected":[{"vendor":"torproject","product":"Tor","defaultStatus":"unaffected","versions":[{"version":"0.2.6.1-alpha","status":"affected","lessThan":"0.4.9.9","versionType":"custom"}]}],"references":["https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog"],"weaknesses":["CWE-1284"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/77xxx/CVE-2026-77640.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77640","state":"PUBLISHED","datePublished":"2026-08-20T21:02:36.470Z","dateUpdated":"2026-08-21T20:08:38.526Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-08-20T21:02:36.115Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"torproject","product":"Tor","defaultStatus":"unaffected","versions":[{"version":"0.2.6.1-alpha","status":"affected","lessThan":"0.4.9.9","versionType":"custom"}]}],"references":[{"url":"https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog"}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1284","description":"CWE-1284 Improper Validation of Specified Quantity in Input","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-08-20T21:02:36.470Z"},"x_generator":{"engine":"CVE-Request-form 0.0.1"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*","versionStartIncluding":"0.2.6.1-alpha","versionEndExcluding":"0.4.9.9"}]}]}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-77640","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-08-21T19:51:18.580818Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-21T20:08:38.526Z"}}]}}}