How severe is CVE-2025-71263?

CVE-2025-71263 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-71263 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-71263?

CVE-2025-71263 affects Opengroup Unix. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-71263?

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-2025-71263 have an EU (EUVD) identifier?

Yes. CVE-2025-71263 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-208655.

When was CVE-2025-71263 published?

CVE-2025-71263 was published on 2026-03-13 and last updated on 2026-06-17.

CVE-2025-71263

CVE-2025-71263 is a high-severity vulnerability in Opengroup Unix with a CVSS 3.x base score of 7.4. 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-120.

Key facts

Severity: High (CVSS 3.x base score 7.4)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-208655
Weakness: CWE-120
Affected product: Opengroup Unix
Published: 2026-03-13
Last modified: 2026-06-17

Description

In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Frequently asked questions

What is CVE-2025-71263?: In UNIX Fourth Research Edition (v4), the su command is vulnerable to a buffer overflow due to the 'password' variable having a fixed size of 100 bytes. A local user can exploit this to gain root privileges. It is unlikely that UNIX v4 is running anywhere outside of a very small number of lab environments. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
How severe is CVE-2025-71263?: CVE-2025-71263 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-71263 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-71263?: CVE-2025-71263 affects Opengroup Unix. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-71263?: 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-2025-71263 have an EU (EUVD) identifier?: Yes. CVE-2025-71263 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-208655.
When was CVE-2025-71263 published?: CVE-2025-71263 was published on 2026-03-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:opengroup:unix:4:*:*:*:*:*:*:*

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