CVE-2026-0400

CVE-2026-0400 is a medium-severity vulnerability in Sonicwall Sonicos with a CVSS 3.x base score of 4.9. 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-134.

Key facts

Description

A post-authentication Format String vulnerability in SonicOS allows a remote attacker to crash a firewall.

Frequently asked questions

What is CVE-2026-0400?
A post-authentication Format String vulnerability in SonicOS allows a remote attacker to crash a firewall.
How severe is CVE-2026-0400?
CVE-2026-0400 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-0400 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.
What products are affected by CVE-2026-0400?
CVE-2026-0400 affects Sonicwall Sonicos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-0400?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-0400 have an EU (EUVD) identifier?
Yes. CVE-2026-0400 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8524.
When was CVE-2026-0400 published?
CVE-2026-0400 was published on 2026-02-24 and last updated on 2026-06-17.

References

Affected products (1)

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