{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93599", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-09-18T11:00:32.755Z", "datePublished": "2026-09-18T13:20:10.258Z", "dateUpdated": "2026-09-18T14:15:25.188Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-09-18T13:20:10.258Z"}, "datePublic": "2026-04-21T00:00:00.000Z", "title": "rustls-webpki before 0.103.13 Panic via empty BIT STRING", "descriptions": [{"lang": "en", "value": "rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1 underflows on the empty slice and the subsequent index operation panics (subtract-with-overflow in debug, index-out-of-bounds in release). The condition is reachable through the public API BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Exploitation requires an application that explicitly opts in to CRL revocation checking by passing RevocationOptions to verify_for_usage() and that parses CRL bytes obtained from a source the attacker can influence; the default rustls configuration, which does not use RevocationOptions, is unaffected. A crafted CRL causes a denial of service via the panic. Fixed in 0.103.13 and 0.104.0-alpha.7."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Integer Underflow (Wrap or Wraparound)", "cweId": "CWE-191", "type": "CWE"}]}], "affected": [{"vendor": "rustls", "product": "webpki", "defaultStatus": "unaffected", "packageURL": "pkg:cargo/rustls-webpki", "versions": [{"version": "0", "status": "affected", "versionType": "semver", "lessThan": "0.103.13"}, {"version": "0.104.0-alpha.1", "status": "affected", "versionType": "semver", "lessThan": "0.104.0-alpha.7"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-82j2-j2ch-gfr8)"}, {"name": "VulnCheck Advisory: rustls-webpki before 0.103.13 Panic via empty BIT STRING", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/rustls-webpki-before-0.103.13-panic-via-empty-bit-string"}], "credits": [{"lang": "en", "value": "tynus3", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}, "x_gcve": [{"vulnId": "CVE-2026-93599", "recordType": "advisory"}]}, "adp": [{"references": [{"url": "https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-18T14:04:54.272751Z", "id": "CVE-2026-93599", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-18T14:15:25.188Z"}}]}, "vulnerability-lookup:meta": {"epss": {"cve": "CVE-2026-93599", "date": "2026-11-08", "epss": "0.00346", "percentile": "0.28385"}, "microsoft_vex": {"current_release_date": "2026-11-02T01:45:32.000Z", "cve": "CVE-2026-93599", "id": "msrc_CVE-2026-93599", "initial_release_date": "2026-09-25T01:04:18.000Z", "product_status:fixed": "2", "product_status:known_affected": "4", "product_status:known_not_affected": "2", "source": "Microsoft CSAF VEX", "status": "final", "title": "rustls-webpki before 0.103.13 Panic via empty BIT STRING", "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-93599.json", "version": "5"}, "nvd": "{\"cve\":{\"id\":\"CVE-2026-93599\",\"sourceIdentifier\":\"disclosure@vulncheck.com\",\"published\":\"2026-09-18T14:19:11.410\",\"lastModified\":\"2026-09-22T20:25:55.870\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1 underflows on the empty slice and the subsequent index operation panics (subtract-with-overflow in debug, index-out-of-bounds in release). The condition is reachable through the public API BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Exploitation requires an application that explicitly opts in to CRL revocation checking by passing RevocationOptions to verify_for_usage() and that parses CRL bytes obtained from a source the attacker can influence; the default rustls configuration, which does not use RevocationOptions, is unaffected. A crafted CRL causes a denial of service via the panic. Fixed in 0.103.13 and 0.104.0-alpha.7.\"}],\"affected\":[{\"source\":\"disclosure@vulncheck.com\",\"affectedData\":[{\"vendor\":\"rustls\",\"product\":\"webpki\",\"defaultStatus\":\"unaffected\",\"packageURL\":\"pkg:cargo/rustls-webpki\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"0.103.13\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"0.104.0-alpha.1\",\"lessThan\":\"0.104.0-alpha.7\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X\",\"baseScore\":8.7,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-09-18T14:04:54.272751Z\",\"id\":\"CVE-2026-93599\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-191\"}]}],\"references\":[{\"url\":\"https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://www.vulncheck.com/advisories/rustls-webpki-before-0.103.13-panic-via-empty-bit-string\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}", "redhat_vex": {"aggregate_severity": "Important", "current_release_date": "2026-11-05T00:11:14+00:00", "cve": "CVE-2026-93599", "id": "CVE-2026-93599", "initial_release_date": "2026-09-18T13:20:10.258000+00:00", "product_status:fixed": "130", "product_status:known_affected": "35", "product_status:known_not_affected": "1169", "source": "Red Hat CSAF VEX", "status": "final", "title": "rustls-webpki: rustls-webpki: Denial of Service via crafted Certificate Revocation List", "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93599.json", "version": "3"}, "vulnrichment": {"containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-93599\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-18T14:04:54.272751Z\"}}}], \"references\": [{\"url\": \"https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-18T14:09:18.314Z\"}}], \"cna\": {\"title\": \"rustls-webpki before 0.103.13 Panic via empty BIT STRING\", \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"tynus3\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 8.7, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\"}}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"rustls\", \"product\": \"webpki\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"0.103.13\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"0.104.0-alpha.1\", \"lessThan\": \"0.104.0-alpha.7\", \"versionType\": \"semver\"}], \"packageURL\": \"pkg:cargo/rustls-webpki\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-04-21T00:00:00.000Z\", \"references\": [{\"url\": \"https://github.com/rustls/webpki/security/advisories/GHSA-82j2-j2ch-gfr8\", \"name\": \"GitHub Security Advisory (GHSA-82j2-j2ch-gfr8)\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://www.vulncheck.com/advisories/rustls-webpki-before-0.103.13-panic-via-empty-bit-string\", \"name\": \"VulnCheck Advisory: rustls-webpki before 0.103.13 Panic via empty BIT STRING\", \"tags\": [\"third-party-advisory\"]}], \"x_generator\": {\"engine\": \"vulncheck-endgame\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"rustls-webpki through 0.103.12 (and 0.104.0-alpha releases before 0.104.0-alpha.7) contains a reachable panic in bit_string_flags() in src/der.rs. The input guard fails to reject a named-bit BIT STRING whose content is exactly [0x00] (zero padding bits and no data bytes), so raw_bits.len() - 1 underflows on the empty slice and the subsequent index operation panics (subtract-with-overflow in debug, index-out-of-bounds in release). The condition is reachable through the public API BorrowedCertRevocationList::from_der() when a CRL contains an issuingDistributionPoint extension with such an onlySomeReasons value. Exploitation requires an application that explicitly opts in to CRL revocation checking by passing RevocationOptions to verify_for_usage() and that parses CRL bytes obtained from a source the attacker can influence; the default rustls configuration, which does not use RevocationOptions, is unaffected. A crafted CRL causes a denial of service via the panic. Fixed in 0.103.13 and 0.104.0-alpha.7.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-191\", \"description\": \"Integer Underflow (Wrap or Wraparound)\"}]}], \"providerMetadata\": {\"orgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"shortName\": \"VulnCheck\", \"dateUpdated\": \"2026-09-18T13:20:10.258Z\"}}}", "cveMetadata": "{\"cveId\": \"CVE-2026-93599\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-09-18T14:15:25.188Z\", \"dateReserved\": \"2026-09-18T11:00:32.755Z\", \"assignerOrgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"datePublished\": \"2026-09-18T13:20:10.258Z\", \"assignerShortName\": \"VulnCheck\"}", "dataType": "CVE_RECORD", "dataVersion": "5.2"}}}
