CVE-2026-55209Network attack vectorHinoki check available

Memory corruption via unchecked GRDECL dimensions and indexes

Published Sep 14, 2026 · Updated Sep 14, 2026

Memory-safety flaws in Equinor ResData before 6.2.9 allow remote attackers to corrupt memory or terminate a service via a crafted GRDECL file. The GRDECL readers accept oversized numeric tokens and inconsistent grid dimensions, keyword lengths, and CORSNUM or ACTNUM indexes before using them in buffer and array operations. Remote reachability requires a network service to pass untrusted GRDECL files into the library; otherwise exploitation requires local control of a parsed file.

CVSS severity9.8
Critical
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Memory-safety flaws in Equinor ResData before 6.2.9 allow remote attackers to corrupt memory or terminate a service via a crafted GRDECL file. The GRDECL readers accept oversized numeric tokens and inconsistent grid dimensions, keyword lengths, and CORSNUM or ACTNUM indexes before using them in buffer and array operations. Remote reachability requires a network service to pass untrusted GRDECL files into the library; otherwise exploitation requires local control of a parsed file.

The record

CVE
CVE-2026-55209
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Equinor
Product
ResData
Classifications
CWE-129, CWE-120, CWE-125, CWE-476, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.2.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Equinor · ResDataversion=< 6.2.9

Published CVSS scores

9.8GitHubCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-125Out-of-bounds Read
CWE-476NULL Pointer Dereference
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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