Auth bypass in Logchimp
CVE-2026-121560
LogChimp 0.9.0-alpha.1 before 0.9.3 contains an authorization bypass vulnerability that allows authenticated post authors to modify any other post by supplying mismatched postId and id body parameters. Attackers can set postId to their own post and id to an enumerated victim post UUID to overwrite its title, slug, content, boardId and roadmap_id.
Vulnerability class: IDOR (Insecure Direct Object Reference)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/logchimp/logchimp/commit/a78b69af342908472ad400285187e43729295a7c (patch)
- github.com/logchimp/logchimp (product)
- github.com/logchimp/logchimp/blob/v0.9.2/packages/server/src/controllers/post/u… (technical-description)
- github.com/logchimp/logchimp/blob/v0.9.2/packages/server/src/middlewares/postEx… (technical-description)
- github.com/logchimp/logchimp/releases/tag/v0.9.3 (release-notes, technical-description)
- www.vulncheck.com/advisories/logchimp-before-0.9.3-authorization-bypass-via-pat… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121560?
- CVE-2026-121560 is a high-severity vulnerability in Logchimp, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.1/10. Published 2026-11-03.
- How severe is CVE-2026-121560?
- High severity. CVSS v3 base score is 7.1 out of 10.