What is CVE-2026-91866?

CVE-2026-91866 is a high-severity vulnerability in Apache Neethi, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-09-21.

How severe is CVE-2026-91866?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Apache Neethi

CVE-2026-91866

A specially crafted pair of WS-Policy documents can force Neethi's policy-intersection to do exponential amounts of work, pinning the CPU for a long time (denial of service). Users are recommended to upgrade to version 3.2.4, which fixes this issue.

Published 2026-09-21 · last modified 2026-09-25.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (54.7th percentile), scored 2026-11-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 54.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

lists.apache.org/thread/zbfxnomgvbmqchqjgc6lk5h0z76k3gh4 (vendor-advisory, Mailing List, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-91866?: CVE-2026-91866 is a high-severity vulnerability in Apache Neethi, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-09-21.
How severe is CVE-2026-91866?: High severity. CVSS v3 base score is 7.5 out of 10.