{"id":"CVE-2026-26981","summary":"OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp","details":"OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4, a heap-buffer-overflow (OOB read) occurs in the `istream_nonparallel_read` function in `ImfContextInit.cpp` when parsing a malformed EXR file through a memory-mapped `IStream`. A signed integer subtraction produces a negative value that is implicitly converted to `size_t`, resulting in a massive length being passed to `memcpy`. Versions 3.3.7 and 3.4.5 contain a patch.","aliases":["GHSA-q6vj-wxvf-5m8c","PYSEC-2026-2849"],"modified":"2026-09-18T14:01:23.625196Z","published":"2026-02-24T02:26:16.659Z","related":["openSUSE-SU-2026:10272-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-195"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26981.json"},"references":[{"type":"ADVISORY","url":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q6vj-wxvf-5m8c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26981.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26981"},{"type":"FIX","url":"https://github.com/AcademySoftwareFoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cef"},{"type":"FIX","url":"https://github.com/AcademySoftwareFoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/academysoftwarefoundation/openexr","events":[{"introduced":"c7d3eac70ccde2c4ed484c6638b83ba872f71464"},{"fixed":"d2b41c84abedf3af0c3b5f2494299037acfa98c3"},{"introduced":"20a65852895894434bea88613f6d29ac8e88bd6e"},{"fixed":"d19b2c3c0bc884a2837e2a60b1caa23dcb5b3296"},{"fixed":"6bb2ddf1068573d073edf81270a015b38cc05cef"},{"fixed":"d2be382758adc3e9ab83a3de35138ec28d93ebd8"}],"database_specific":{"cpe":"cpe:2.3:a:openexr:openexr:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"3.3.0"},{"fixed":"3.3.7"},{"introduced":"3.4.0"},{"fixed":"3.4.5"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v3.4.5-rc","v3.3.7-rc3","v3.3.7-rc2","v3.3.7-rc","v3.3.6","v3.4.4-rc2","v3.4.4","v3.4.4-rc","v3.4.3-rc3","v3.4.3","v3.3.6-rc4","v3.3.6-rc3","v3.4.3-rc2","v3.3.6-rc2","v3.4.3-rc","v3.3.6-rc","v3.3.5","v3.4.2-rc2","v3.4.2","v3.4.2-rc","v3.4.1-rc2","v3.4.1","v3.4.1-rc","v3.4.0","v3.3.5-rc3","v3.3.5-rc","v3.3.4-rc","v3.3.4","v3.3.3-rc1","v3.3.3","v3.3.3-rc","v3.3.2-rc4","v3.3.2","v3.3.2-rc3","v3.3.2-rc2","v3.3.2-rc","v3.3.1-rc","v3.3.1","v3.3.0-rc2","v3.3.0"],"database_specific":{"vanir_signatures":[{"id":"CVE-2026-26981-5a525b97","signature_type":"Function","signature_version":"v1","source":"https://github.com/academysoftwarefoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8","target":{"file":"src/lib/OpenEXR/ImfContextInit.cpp","function":"istream_nonparallel_read"},"deprecated":false,"digest":{"length":1486,"function_hash":"203178239813441149423426696725067004647"}},{"source":"https://github.com/academysoftwarefoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cef","target":{"file":"src/lib/OpenEXR/ImfContextInit.cpp","function":"istream_nonparallel_read"},"deprecated":false,"digest":{"function_hash":"203178239813441149423426696725067004647","length":1486},"id":"CVE-2026-26981-5a646843","signature_type":"Function","signature_version":"v1"},{"deprecated":false,"digest":{"line_hashes":["201273958621668520371750826698792441326","120460579602726193602003540117105330515","141391920219548362044519675177848764342","161735030611050642409771232174642374808","14794179868677938007826040057612910107","114259587418400404575152605867966412692","186364034641259611919768213429269351078","114884463824472841261294685087723496704"],"threshold":0.9},"id":"CVE-2026-26981-b85cb1d7","signature_type":"Line","signature_version":"v1","source":"https://github.com/academysoftwarefoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cef","target":{"file":"src/lib/OpenEXR/ImfContextInit.cpp"}},{"signature_type":"Line","signature_version":"v1","source":"https://github.com/academysoftwarefoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8","target":{"file":"src/lib/OpenEXR/ImfContextInit.cpp"},"deprecated":false,"digest":{"line_hashes":["201273958621668520371750826698792441326","120460579602726193602003540117105330515","141391920219548362044519675177848764342","161735030611050642409771232174642374808","14794179868677938007826040057612910107","114259587418400404575152605867966412692","186364034641259611919768213429269351078","114884463824472841261294685087723496704"],"threshold":0.9},"id":"CVE-2026-26981-b941da6f"}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-26981.json","vanir_signatures_modified":"2026-09-18T14:01:23Z"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}