{"id":"CVE-2026-55209","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-55209","generatedAt":"2026-09-20T15:03:26.577Z","title":"In a network service that accepts untrusted GRDECL files, these conditions can cause a classic buffer overflow, out-of-bounds reads, invalid array access, NULL pointer dereference, memory corruption, or service termination.","description":"resdata is software for reading and writing result files from the Eclipse reservoir simulator. Prior to 6.2.9, resdata insufficiently validates numeric fields, grid dimensions, keyword sizes, and array indexes while parsing untrusted GRDECL files in lib/resdata/rd_kw_grdecl.cpp and lib/resdata/rd_grid.cpp. Malformed COORD, ZCORN, CORSNUM, ACTNUM, or MAPAXES data can reach rd_grid_alloc_GRDECL_kw__ with inconsistent lengths, while unbounded floating-point conversion can exceed the intended parser buffer. In a network service that accepts untrusted GRDECL files, these conditions can cause a classic buffer overflow, out-of-bounds reads, invalid array access, NULL pointer dereference, memory corruption, or service termination. This issue is fixed in version 6.2.9.","published":"2026-09-14T20:16:47.000Z","lastModified":"2026-09-14T21:17:13.000Z","status":"Received","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-120","CWE-125","CWE-129","CWE-476"],"affected":[],"epss":{"score":0.00421,"percentile":0.3604,"date":"2026-09-19","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.42%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/equinor/resdata/commit/9f8fd6db472e0696080b768389914d60a453904f","source":"security-advisories@github.com"},{"url":"https://github.com/equinor/resdata/commit/d3f45828e9413506b8e8160a9304f4b7b06dcefc","source":"security-advisories@github.com"},{"url":"https://github.com/equinor/resdata/commit/ee8cc12b026d945df3077bc98e211ee45f80a433","source":"security-advisories@github.com"},{"url":"https://github.com/equinor/resdata/pull/1166","source":"security-advisories@github.com"},{"url":"https://github.com/equinor/resdata/releases/tag/6.2.9","source":"security-advisories@github.com"},{"url":"https://github.com/equinor/resdata/security/advisories/GHSA-pr85-w493-9w3x","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55209","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}