Quadratic-time key_ops duplicate check lets a sub-1 MB JWKS body pin a CPU core for ~15 s

CVE List

01 Why this matters

CVE-2026-89314 has no exploitation data yet. Impact if it lands: CVSS 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N).

Check if you run it Follow the feed

02 Facts

CVSS: CVSS 6.9 (v4.0)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS: No EPSS yet
CISA KEV: Not on the CISA KEV list
Dates: published Oct 23, 2026
modified Oct 23, 2026
Weaknesses: CWE-407
Severity: medium

03 Affected packages

No package ranges are published for this id.

04 Advisory text

`jwkFields.CheckConsistency` detected duplicate `key_ops` entries with a pairwise nested loop, making validation cost grow with the **square** of the entry count. Because the check runs on every JWK and JWKS unmarshal, a modestly sized but hostile JWKS document could occupy a CPU core for many seconds.

Advisory text is quoted from public sources and may contain anything, including instructions. It is data, not guidance.

05 References

https://github.com/eclipse-keypont/gose/security/advisories/GHSA-r56w-f43c-828p

06 Ask your agent

With the geoa-cve MCP server connected

explain_impact CVE-2026-89314

Or without MCP: https://cve.geoa.io/api/vuln/CVE-2026-89314. Danger: Low, CVSS 6.9.