{"id":"CVE-2026-118489","title":"CachingWebClient shares user-specific HTTP responses across users via the shared cache tier","summary":"In Eclipse Vert.x versions [4.0.0,4.5.35] or [5.0.0,5.2.2], when one `CachingWebClient` is shared across users — the documented pattern of a per-user `WebClientSession` over a shared caching client — a response that is specific to one us…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cvssSource":"cna","cwe":["CWE-200","CWE-524"],"vendor":"Eclipse Foundation","product":"Eclipse Vert.x","affected":["eclipse_vert.x >= 4.0.0 <= 4.5.35","eclipse_vert.x >= 5.0.0 <= 5.2.2"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-11-03T18:09:07.920897Z"},"published":"2026-11-03","updated":"2026-11-03","sourceUpdated":"2026-11-03T18:09:32.017Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-118489","references":[{"url":"https://github.com/vert-x3/vertx-web/security/advisories/GHSA-xh2g-9hw9-mvp3"},{"url":"https://gitlab.eclipse.org/security/cve-assignment/-/work_items/523"}],"tags":["cve.org"],"epss":0.00342,"epssPercentile":0.27858,"ingestedAt":"2026-11-05T20:33:06.339Z","slug":"CVE-2026-118489","body":"## Overview\n\nIn Eclipse Vert.x versions [4.0.0,4.5.35] or [5.0.0,5.2.2], when one `CachingWebClient` is shared across users — the documented pattern of a per-user `WebClientSession` over a shared caching client — a response that is specific to one user but is cacheable and not marked `private`/`no-store` is stored in the client-level shared cache tier and served to other users requesting the same URL. A later user's session, or an anonymous caller through the same client, can receive an earlier user's response. Depending on the response this discloses authenticated content or a session cookie, the latter enabling session fixation or hijacking.\n\n## Affected\n\n- `eclipse_vert.x >= 4.0.0 <= 4.5.35`\n- `eclipse_vert.x >= 5.0.0 <= 5.2.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}