{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-77639", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "state": "PUBLISHED", "assignerShortName": "mitre", "dateReserved": "2026-08-20T20:57:49.855Z", "datePublished": "2026-08-20T20:57:50.207Z", "dateUpdated": "2026-08-20T20:57:50.207Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Tor", "vendor": "torproject", "versions": [{"lessThan": "0.4.9.9", "status": "affected", "version": "0.3.1.1-alpha", "versionType": "custom"}]}], "descriptions": [{"lang": "en", "value": "Tor before 0.4.9.9 was prone to a\u00a0compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022."}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/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-420", "description": "CWE-420 Unprotected Alternate Channel", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-08-20T20:57:50.207Z"}, "references": [{"url": "https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog"}], "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": "0.3.1.1-alpha", "versionEndExcluding": "0.4.9.9"}]}]}]}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Tor", "vendor": "torproject", "versions": [{"lessThan": "0.4.9.9", "status": "affected", "version": "0.3.1.1-alpha", "versionType": "custom"}]}], "source": "[email protected]"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Tor before 0.4.9.9 was prone to a\u00a0compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022."}], "id": "CVE-2026-77639", "lastModified": "2026-08-20T21:17:11.233", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "[email protected]", "type": "Secondary"}]}, "published": "2026-08-20T21:17:11.233", "references": [{"source": "[email protected]", "url": "https://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.9/ChangeLog"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-420"}], "source": "[email protected]", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0.3.1.1-alpha,0.4.9.9)"}}], "enrichment": {"confidence": 90.0, "confidence_source": "inferred", "scores": [{"score": 90.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Tor", "source": "cna", "vendor": "torproject"}, "product": "tor", "vendor": "torproject"}], "created": "2026-08-21T00:15:03.151454+00:00", "title": "Compression Bomb Bypass Vulnerability in Tor", "updated": "2026-08-21T01:15:07.281001+00:00", "vendors": ["torproject", "torproject$PRODUCT$tor"]}