How severe is CVE-2026-91803?

CVE-2026-91803 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-91803 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-91803?

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.

When was CVE-2026-91803 published?

CVE-2026-91803 was published on 2026-09-23.

CVE-2026-91803

CVE-2026-91803 is a high-severity vulnerability with a CVSS 3.x base score of 8.8. 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-427.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-427
Published: 2026-09-23
Last modified: 2026-09-23

Description

A local privilege escalation vulnerability exists in the updater of Foxit PDF Editor/Reader due to unsafe loading of dynamic-link libraries from a user-writable directory during high-privilege operations. A local attacker could exploit this issue to execute code with elevated privileges.

Frequently asked questions

What is CVE-2026-91803?: A local privilege escalation vulnerability exists in the updater of Foxit PDF Editor/Reader due to unsafe loading of dynamic-link libraries from a user-writable directory during high-privilege operations. A local attacker could exploit this issue to execute code with elevated privileges.
How severe is CVE-2026-91803?: CVE-2026-91803 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-91803 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-91803?: 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.
When was CVE-2026-91803 published?: CVE-2026-91803 was published on 2026-09-23.

References

https://www.foxit.com/support/security-bulletins.html

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