How severe is CVE-2025-40833?

CVE-2025-40833 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-40833 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.

How do I fix CVE-2025-40833?

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

Does CVE-2025-40833 have an EU (EUVD) identifier?

Yes. CVE-2025-40833 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209778.

When was CVE-2025-40833 published?

CVE-2025-40833 was published on 2026-05-12 and last updated on 2026-06-17.

CVE-2025-40833

CVE-2025-40833 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-209778
Weakness: CWE-476
Published: 2026-05-12
Last modified: 2026-06-17

Description

The affected devices contain a null pointer dereference vulnerability while processing specially crafted IPv4 requests. This could allow an attacker to cause denial of service condition. A manual restart is required to recover the system.

Frequently asked questions

What is CVE-2025-40833?: The affected devices contain a null pointer dereference vulnerability while processing specially crafted IPv4 requests. This could allow an attacker to cause denial of service condition. A manual restart is required to recover the system.
How severe is CVE-2025-40833?: CVE-2025-40833 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-40833 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.
How do I fix CVE-2025-40833?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-40833 have an EU (EUVD) identifier?: Yes. CVE-2025-40833 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209778.
When was CVE-2025-40833 published?: CVE-2025-40833 was published on 2026-05-12 and last updated on 2026-06-17.

References

https://cert-portal.siemens.com/productcert/html/ssa-392349.html

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