CVE-2026-91855

MEDIUM
Published Sep 15, 2026 Modified Sep 16, 2026 CWE-404

Description

A security flaw has been discovered in Open5GS up to 2.7.7. Affected by this vulnerability is an unknown functionality of the file lib/pfcp/handler.c of the component PFCP Message Handler. Performing a manipulation results in denial of service. Remote exploitation of the attack is possible. The exploit has been released to the public and may be used for attacks. The patch is named 028e1dbb5e3271035ccee906ef417a97fc523f71. Applying a patch is the recommended action to fix this issue. CVE-2025-29339 describes a different assertion failure vulnerability in Open5GS UPF.

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CVSS v3.1 Score

5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0042
Probability of exploitation
0.36%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-404 CWE-404

References

Frequently Asked Questions

What is CVE-2026-91855? +
A security flaw has been discovered in Open5GS up to 2.7.7. Affected by this vulnerability is an unknown functionality of the file lib/pfcp/handler.c of the component PFCP Message Handler. Performing a manipulation results in denial of service. Remote exploitation of the attack is possible. The exploit has been released to the public and may be used for attacks. The patch is named 028e1dbb5e3271035ccee906ef417a97fc523f71. Applying a patch is the recommended action to fix this issue. CVE-2025-29339 describes a different assertion failure vulnerability in Open5GS UPF. It has a CVSS v3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2026-91855? +
CVE-2026-91855 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0042, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-91855? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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