How severe is CVE-2026-67873?

CVE-2026-67873 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-67873 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-67873?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-67873 published?

CVE-2026-67873 was published on 2026-08-06.

CVE-2026-67873

CVE-2026-67873 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-122
Published: 2026-08-06
Last modified: 2026-08-06

Description

A heap-based buffer overflow exists in lib60870-C 2.4.0 in the server-side FileSegment ASDU encoding path. The issue occurs because FileSegment_encode() validates only the standalone segment length via FileSegment_GetMaxDataSize() and does not verify the residual capacity of the current ASDU frame before encoding object fields and segment data

Frequently asked questions

What is CVE-2026-67873?: A heap-based buffer overflow exists in lib60870-C 2.4.0 in the server-side FileSegment ASDU encoding path. The issue occurs because FileSegment_encode() validates only the standalone segment length via FileSegment_GetMaxDataSize() and does not verify the residual capacity of the current ASDU frame before encoding object fields and segment data
How severe is CVE-2026-67873?: CVE-2026-67873 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-67873 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-67873?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-67873 published?: CVE-2026-67873 was published on 2026-08-06.

References

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