{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-39886","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-04-07T20:32:03.011Z","datePublished":"2026-04-21T01:27:01.371Z","dateUpdated":"2026-04-21T13:49:21.573Z"},"containers":{"cna":{"title":"OpenEXR has HTJ2K Signed Integer Overflow in ht_undo_impl()","problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","description":"CWE-190: Integer Overflow or Wraparound","type":"CWE"}]}],"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"}}],"references":[{"name":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-r3mr-mx8q-jcw5","tags":["x_refsource_CONFIRM"],"url":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-r3mr-mx8q-jcw5"},{"name":"https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.10","tags":["x_refsource_MISC"],"url":"https://github.com/AcademySoftwareFoundation/openexr/releases/tag/v3.4.10"}],"affected":[{"vendor":"AcademySoftwareFoundation","product":"openexr","versions":[{"version":">= 3.4.0, < 3.4.10","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-04-21T01:27:01.371Z"},"descriptions":[{"lang":"en","value":"OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. Versions 3.4.0 through 3.4.9 have a signed integer overflow vulnerability in OpenEXR's HTJ2K (High-Throughput JPEG 2000) decompression path. The `ht_undo_impl()` function in `src/lib/OpenEXRCore/internal_ht.cpp` accumulates a bytes-per-line value (`bpl`) using a 32-bit signed integer with no overflow guard. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K maximum width of 32,767 causes `bpl` to overflow `INT_MAX`, producing undefined behavior confirmed by UBSan. On an\nallocator-permissive host where the required ~64 GB allocation succeeds, the wrapped negative `bpl` value would subsequently be used as a per-scanline pointer advance, which would produce a heap out-of-bounds write. On a memory-constrained host, the allocation fails before `ht_undo_impl()` is entered. This is the second distinct integer overflow in `ht_undo_impl()`. CVE-2026-34545 addressed a different overflow in the same function — the `int16_t p` pixel-loop counter at line ~302 that overflows when iterating over channels whose `width` exceeds 32,767. The CVE-2026-34545 fix did not touch the `int bpl` accumulator at line 211, which is the subject of this advisory. The `bpl` accumulator was also not addressed by any of the 8 advisories in the 2026-04-05 v3.4.9 release batch. This finding is structurally identical to CVE-2026-34588 (PIZ `wcount*nx` overflow in `internal_piz.c`) and should be remediated with the same pattern. The CVE-2026-34588 fix did not touch `internal_ht.cpp`. Version 3.4.10 contains a remediation that addresses the vulnerability in `internal_ht.cpp`."}],"source":{"advisory":"GHSA-r3mr-mx8q-jcw5","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T13:49:09.656578Z","id":"CVE-2026-39886","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":"2026-04-21T13:49:21.573Z"}}]}}