CVE-2026-40984: Micrometer HTTP server instrumentations DoS vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-09 · updated 2026-09-14
Weakness: CWE-400

Description

In Micrometer, it is possible for a user to provide specially crafted HTTP requests that may cause a denial-of-service (DoS) condition. Affected versions: micrometer-core 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18; 1.9.0 through 1.9.17. micrometer-jetty11 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18. micrometer-jetty12 1.16.0 through 1.16.5; 1.15.0 through 1.15.11; 1.14.0 through 1.14.15; 1.13.0 through 1.13.18.

Affected products

Spring Micrometer: from 1.16.0 before 1.16.5.1; from 1.15.0 before 1.15.11.1; from 1.14.0 before 1.14.16; from 1.13.0 before 1.13.19; from 1.9.0 before 1.9.18; from 1.16.0 before 1.16.6 — fixed in 1.13.19, 1.14.15.1, 1.14.16, 1.15.11., 1.15.11.1, 1.16.5.1

How to fix

Upgrade to a fixed version: Spring Micrometer 1.13.19, 1.14.15.1, 1.14.16, 1.15.11.. Check the vendor advisory for mitigations.

References

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