{"id":"CVE-2026-55373","state":"PUBLISHED","title":"OpenEXR: OpenEXRUtil SampleCountChannel endEdit() can loop forever on UINT_MAX sample counts","description":"OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12, and 3.4.13 contain an infinite-loop vulnerability in SampleCountChannel. The helper roundListSizeUp() rounds a sample-list size up to the next power of two using repeated unsigned left shifts, which terminates for normal values but fails for UINT_MAX: the sequence reaches 0x80000000, and the next left shift wraps the 32-bit value to 0. Because 0 remains less than UINT_MAX, the loop never progresses and never exits. The bug is reachable through public OpenEXRUtil APIs, either by editing the sample-count buffer through SampleCountChannel::Edit (whose destructor calls endEdit()) or by calling SampleCountChannel::set(x, y, UINT_MAX) on a valid pixel. This issue has been fixed in versions 3.2.10, 3.3.12, and 3.4.13.","publishedAt":"2026-08-25T00:39:45.185Z","updatedAt":"2026-08-25T13:37:33.398Z","severity":{"score":6.2,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["AcademySoftwareFoundation openexr"],"affected":[{"vendor":"AcademySoftwareFoundation","product":"openexr","versions":[{"version":"< 3.2.10","status":"affected"},{"version":">= 3.3.0, < 3.3.12","status":"affected"},{"version":">= 3.4.0, < 3.4.13","status":"affected"}]}],"references":["https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-mff9-68x3-h8rh"],"weaknesses":["CWE-190","CWE-400","CWE-835"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55373.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55373","state":"PUBLISHED","datePublished":"2026-08-25T00:39:45.185Z","dateUpdated":"2026-08-25T13:37:33.398Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T18:57:40.181Z"},"containers":{"cna":{"title":"OpenEXR: OpenEXRUtil SampleCountChannel endEdit() can loop forever on UINT_MAX sample counts","descriptions":[{"lang":"en","value":"OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12, and 3.4.13 contain an infinite-loop vulnerability in SampleCountChannel. The helper roundListSizeUp() rounds a sample-list size up to the next power of two using repeated unsigned left shifts, which terminates for normal values but fails for UINT_MAX: the sequence reaches 0x80000000, and the next left shift wraps the 32-bit value to 0. Because 0 remains less than UINT_MAX, the loop never progresses and never exits. The bug is reachable through public OpenEXRUtil APIs, either by editing the sample-count buffer through SampleCountChannel::Edit (whose destructor calls endEdit()) or by calling SampleCountChannel::set(x, y, UINT_MAX) on a valid pixel. This issue has been fixed in versions 3.2.10, 3.3.12, and 3.4.13."}],"affected":[{"vendor":"AcademySoftwareFoundation","product":"openexr","versions":[{"version":"< 3.2.10","status":"affected"},{"version":">= 3.3.0, < 3.3.12","status":"affected"},{"version":">= 3.4.0, < 3.4.13","status":"affected"}]}],"references":[{"url":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-mff9-68x3-h8rh","name":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-mff9-68x3-h8rh","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":6.2,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","description":"CWE-190: Integer Overflow or Wraparound","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-835","lang":"en","description":"CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-25T00:39:45.185Z"},"source":{"advisory":"GHSA-mff9-68x3-h8rh","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-mff9-68x3-h8rh","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T13:37:26.507149Z","id":"CVE-2026-55373","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-25T13:37:33.398Z"}}]}}}