resdata insufficiently validates untrusted GRDECL files

published 2026-08-18 2 mo ago modified 2026-09-30 39 d ago also GHSA-pr85-w493-9w3x , PYSEC-2026-3694 , EUVD-2026-77802

cvss: 9.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 5

pypi resdata 6.2.9

github.com/equinor/resdata@9f8fd6d commit
github.com/equinor/resdata@d3f4582 commit
github.com/equinor/resdata@ee8cc12 commit
github.com/equinor/resdata#1166 pull request
github.com/equinor/resdata/releases/tag/6.2.9 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 55 d ago (2026-09-14)

Exploit prediction

0.78% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
pypi	resdata	<6.2.9	6.2.9

Affected products

equinor resdata

Classification

Weakness

CWE-120 Buffer Copy without Checking Size of Input
CWE-125 Out-of-bounds Read
CWE-129 Improper Validation of Array Index
CWE-476 NULL Pointer Dereference

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary