Quick answers
- Is CVE-2026-118489 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-118489 being exploited in the wild.
- How severe is CVE-2026-118489?
- High severity, with a CVSS score of 7.5, published 3 November 2026.
- Which products and versions are affected?
- Eclipse Vert.X [4.0.0, 4.5.35], [5.0.0, 5.2.2].
- Is there a fix for CVE-2026-118489?
- Yes: fixed in Vert.x 4.5.36, 5.2.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-118489 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-118489?
- Check whether you run Eclipse Vert.X at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Vert.x 4.5.36, 5.2.3
Technical details
The CachingWebClient shares a cache key that does not incorporate per-user markers; the CacheInterceptor decides to store responses in the shared cache based only on Cache-Control and Expires headers, ignoring RFC 9111 requirements for shared caches. Responses bearing Authorization headers or Set-Cookie headers are cached and replayed across users despite lacking explicit shareability directives. An attacker exploiting this requires a shared CachingWebClient instance across user principals and relies on the origin server omitting private/no-store directives on cacheable responses.
Affected products
- Eclipse Vert.x [4.0.0, 4.5.35], [5.0.0, 5.2.2]
Timeline
- 2026-11-03: disclosed