{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-120251", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-10-31T22:06:00.527Z", "datePublished": "2026-11-01T00:57:14.911Z", "dateUpdated": "2026-11-01T00:57:14.911Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-01T00:57:14.911Z"}, "datePublic": "2026-10-10T00:00:00.000Z", "title": "imagecodecs 2026.3.6 through 2026.10.10 Infinite Loop via ccittfax4_decode()", "descriptions": [{"lang": "en", "value": "imagecodecs 2026.3.6 through 2026.10.10 contains an infinite loop vulnerability in ccitt_fax4_decode_size() that allows attackers to hang the calling process by supplying a crafted CCITT Group 4 stream. Attackers can provide an 8-byte G4 stream lacking EOFB to ccittfax4_decode() or the numcodecs Ccittfax4 codec, consuming full CPU until the process is killed."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Loop with Unreachable Exit Condition ('Infinite Loop')", "cweId": "CWE-835", "type": "CWE"}]}], "affected": [{"vendor": "cgohlke", "product": "imagecodecs", "defaultStatus": "unaffected", "versions": [{"version": "2026.3.6", "lessThanOrEqual": "2026.10.10", "status": "affected", "versionType": "custom"}], "packageURL": "pkg:pypi/imagecodecs", "repo": "https://github.com/cgohlke/imagecodecs"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM"}}], "references": [{"url": "https://github.com/cgohlke/imagecodecs/issues/158", "tags": ["issue-tracking"], "name": "GitHub Issue #158"}, {"url": "https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449", "tags": ["technical-description"]}, {"url": "https://github.com/cgohlke/imagecodecs", "tags": ["product"]}, {"name": "VulnCheck Advisory: imagecodecs 2026.3.6 through 2026.10.10 Infinite Loop via ccittfax4_decode()", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode"}], "credits": [{"lang": "en", "value": "Dilanka Kaushal Hewage (r3vpwnx)", "type": "finder"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:pypi/imagecodecs", "product": "imagecodecs", "repo": "https://github.com/cgohlke/imagecodecs", "vendor": "cgohlke", "versions": [{"lessThanOrEqual": "2026.10.10", "status": "affected", "version": "2026.3.6", "versionType": "custom"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "imagecodecs 2026.3.6 through 2026.10.10 contains an infinite loop vulnerability in ccitt_fax4_decode_size() that allows attackers to hang the calling process by supplying a crafted CCITT Group 4 stream. Attackers can provide an 8-byte G4 stream lacking EOFB to ccittfax4_decode() or the numcodecs Ccittfax4 codec, consuming full CPU until the process is killed."}], "id": "CVE-2026-120251", "lastModified": "2026-11-02T19:34:23.993", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-11-01T01:17:19.110", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/cgohlke/imagecodecs"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/cgohlke/imagecodecs/issues/158"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-835"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{"bugzilla": {"description": "imagecodecs: imagecodecs: Denial of Service via infinite loop in CCITT Group 4 decoding", "id": "2564500", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2564500"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-835", "details": ["imagecodecs 2026.3.6 through 2026.10.10 contains an infinite loop vulnerability in ccitt_fax4_decode_size() that allows attackers to hang the calling process by supplying a crafted CCITT Group 4 stream. Attackers can provide an 8-byte G4 stream lacking EOFB to ccittfax4_decode() or the numcodecs Ccittfax4 codec, consuming full CPU until the process is killed.", "A flaw was found in imagecodecs. This vulnerability allows an attacker to cause a Denial of Service (DoS) by tricking a user or application into processing a specially crafted CCITT Group 4 fax image stream. An infinite loop in the fax decoding routine causes the process to consume excessive CPU resources and hang indefinitely until terminated."], "mitigation": {"lang": "en:us", "value": "Avoid decoding untrusted or fax-compressed (CCITT G4/T4) image streams with imagecodecs; constrain or kill decoding processes processing untrusted input until a fixed release is published."}, "name": "CVE-2026-120251", "public_date": "2026-11-01T00:57:14Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-120251\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-120251\nhttps://github.com/cgohlke/imagecodecs\nhttps://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449\nhttps://github.com/cgohlke/imagecodecs/issues/158\nhttps://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode"], "statement": "imagecodecs 2026.3.6 through 2026.10.10 contains an infinite loop in ccitt_fax4_decode_size()/ccitt_decode_2d_line when decoding a crafted CCITT Group 4 fax stream lacking EOFB, causing excessive CPU consumption and a hang of the calling process. No fixed release exists yet.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2026.3.6,2026.10.10]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "imagecodecs", "source": "cna", "vendor": "cgohlke"}, "product": "imagecodecs", "vendor": "cgohlke"}], "created": "2026-11-01T02:30:18.623474+00:00", "updated": "2026-11-03T16:31:02.227699+00:00", "vendors": ["cgohlke", "cgohlke$PRODUCT$imagecodecs"]}