How severe is CVE-2026-86131?

CVE-2026-86131 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-2026-86131 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-86131?

CVE-2026-86131 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-86131?

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-2026-86131 published?

CVE-2026-86131 was published on 2026-09-30 and last updated on 2026-10-06.

CVE-2026-86131

CVE-2026-86131 is a critical-severity vulnerability in Watchguard Fireware 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-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 9.2
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Watchguard Fireware
Published: 2026-09-30
Last modified: 2026-10-06

Description

A code injection vulnerability in WatchGuard Fireware OS's BOVPN Over TLS client configuration handling allows an attacker who controls the remote VPN server to execute arbitrary commands as root on the connecting Firebox.

Frequently asked questions

What is CVE-2026-86131?: A code injection vulnerability in WatchGuard Fireware OS's BOVPN Over TLS client configuration handling allows an attacker who controls the remote VPN server to execute arbitrary commands as root on the connecting Firebox.
How severe is CVE-2026-86131?: CVE-2026-86131 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-2026-86131 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-86131?: CVE-2026-86131 affects Watchguard Fireware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-86131?: 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-2026-86131 published?: CVE-2026-86131 was published on 2026-09-30 and last updated on 2026-10-06.

References

https://psirt.watchguard.com/CVE-2026-86131

Affected products (1)

cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:*

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