resdata insufficiently validates untrusted GRDECL files
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution, Denial of service
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-120, CWE-476 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| equinor | resdata | before 6.2.9 | 6.2.9 | Patch available | CNA |
| — | resdata (PyPI) | before 6.2.9 | 6.2.9 | Patch available | GHSA-pr85-w493-9w3x |
- resdata Vendorequinor Affected before 6.2.9 Fixed in 6.2.9 Patch available CNA
- resdata (PyPI) Vendor— Affected before 6.2.9 Fixed in 6.2.9 Patch available GHSA-pr85-w493-9w3x
Remediation
- Fix · CNA resdata (equinor) Fixed in 6.2.9
- Fix · GHSA-pr85-w493-9w3x resdata (PyPI) Fixed in 6.2.9 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55209
- 2026-10-03 Alias added: GHSA-pr85-w493-9w3x
References
Other 7
- https://github.com/equinor/resdata/security/advisories/GHSA-pr85-w493-9w3x
- https://github.com/equinor/resdata/pull/1166
- https://github.com/equinor/resdata/commit/9f8fd6db472e0696080b768389914d60a453904f
- https://github.com/equinor/resdata/commit/d3f45828e9413506b8e8160a9304f4b7b06dcefc
- https://github.com/equinor/resdata/commit/ee8cc12b026d945df3077bc98e211ee45f80a433
- https://github.com/equinor/resdata/releases/tag/6.2.9
- https://github.com/equinor/resdata
More equinor vulnerabilities
- TI-2026-39891 surfio IRAP header size fields cause out-of-bounds reads CVSS 3.0CRITICAL 9.8
Sources
- CVE-2026-55209 · CVE Program
- CVE-2026-55209 · NVD
- FIRST EPSS
- GHSA-pr85-w493-9w3x · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences