How severe is CVE-2025-40600?

CVE-2025-40600 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-2025-40600 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-40600?

CVE-2025-40600 affects Sonicwall Sonicos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-40600?

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.

Does CVE-2025-40600 have an EU (EUVD) identifier?

Yes. CVE-2025-40600 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-23048.

When was CVE-2025-40600 published?

CVE-2025-40600 was published on 2025-07-29 and last updated on 2026-06-17.

CVE-2025-40600

CVE-2025-40600 is a critical-severity vulnerability in Sonicwall Sonicos 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-134.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-23048
Weakness: CWE-134
Affected product: Sonicwall Sonicos
Published: 2025-07-29
Last modified: 2026-06-17

Description

Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.

Frequently asked questions

What is CVE-2025-40600?: Use of Externally-Controlled Format String vulnerability in the SonicOS SSL VPN interface allows a remote unauthenticated attacker to cause service disruption.
How severe is CVE-2025-40600?: CVE-2025-40600 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-2025-40600 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-40600?: CVE-2025-40600 affects Sonicwall Sonicos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-40600?: 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.
Does CVE-2025-40600 have an EU (EUVD) identifier?: Yes. CVE-2025-40600 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-23048.
When was CVE-2025-40600 published?: CVE-2025-40600 was published on 2025-07-29 and last updated on 2026-06-17.

References

https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2025-0013

Affected products (1)

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

More vulnerabilities in Sonicwall Sonicos

CVE-2024-53704 — Critical (CVSS 9.8): An Improper Authentication vulnerability in the SSLVPN authentication mechanism allows a remote attacker to bypass…
CVE-2024-40766 — Critical (CVSS 9.8): An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially…
CVE-2024-22394 — Critical (CVSS 9.8): An improper authentication vulnerability has been identified in SonicWall SonicOS SSL-VPN feature, which in specific…
CVE-2022-22274 — Critical (CVSS 9.8): A Stack-based buffer overflow vulnerability in the SonicOS via HTTP request allows a remote unauthenticated attacker to…
CVE-2020-5135 — Critical (CVSS 9.8): A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially…
CVE-2019-12261 — Critical (CVSS 9.8): Wind River VxWorks 6.7 though 6.9 and vx7 has a Buffer Overflow in the TCP component (issue 3 of 4). This is an IPNET…

All CVEs affecting Sonicwall Sonicos →

Other CWE-134 vulnerabilities

CVE-2012-1851 — Critical (CVSS 10.0): Format string vulnerability in the Print Spooler service in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2,…
CVE-2012-0242 — Critical (CVSS 10.0): Format string vulnerability in Advantech/BroadWin WebAccess before 7.0 allows remote attackers to execute arbitrary…
CVE-2011-2475 — Critical (CVSS 10.0): Format string vulnerability in ECTrace.dll in the iMailGateway service in the Internet Mail Gateway in OneBridge Server…
CVE-2011-1568 — Critical (CVSS 10.0): Format string vulnerability in the logText function in shmemmgr9.dll in IGSSdataServer.exe 9.00.00.11074, and…
CVE-2010-4235 — Critical (CVSS 10.0): Format string vulnerability in RealNetworks Helix Server 12.x, 13.x, and 14.x before 14.2, and Helix Mobile Server…
CVE-2011-0270 — Critical (CVSS 10.0): Format string vulnerability in nnmRptConfig.exe in HP OpenView Network Node Manager (OV NNM) 7.51 and 7.53 allows…

Browse all CWE-134 vulnerabilities →