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{"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"}