How severe is CVE-2026-0399?

CVE-2026-0399 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-2026-0399 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-0399?

CVE-2026-0399 affects Sonicwall Sonicos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-0399?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-0399 have an EU (EUVD) identifier?

Yes. CVE-2026-0399 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8525.

When was CVE-2026-0399 published?

CVE-2026-0399 was published on 2026-02-24 and last updated on 2026-06-17.

CVE-2026-0399

CVE-2026-0399 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-121.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8525
Weakness: CWE-121
Affected product: Sonicwall Sonicos
Published: 2026-02-24
Last modified: 2026-06-17

Description

Multiple post-authentication stack-based buffer overflow vulnerabilities in the SonicOS management interface due to improper bounds checking in a API endpoint.

Frequently asked questions

What is CVE-2026-0399?: Multiple post-authentication stack-based buffer overflow vulnerabilities in the SonicOS management interface due to improper bounds checking in a API endpoint.
How severe is CVE-2026-0399?: CVE-2026-0399 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-2026-0399 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-0399?: CVE-2026-0399 affects Sonicwall Sonicos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-0399?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-0399 have an EU (EUVD) identifier?: Yes. CVE-2026-0399 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8525.
When was CVE-2026-0399 published?: CVE-2026-0399 was published on 2026-02-24 and last updated on 2026-06-17.

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0001

Affected products (1)

cpe:2.3:o:sonicwall:sonicos:*:*:*:*:*:*:*:*

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