Auth bypass in Jeremyckahn Chitchatter
CVE-2026-118129
A vulnerability was found in jeremyckahn Chitchatter up to f82538633813c854a81a8b2112a2f6ba17b39cbc. The affected element is the function isConfigMessageEvent of the file src/Bootstrap.tsx of the component PostMessage Handler. Performing a manipulation of the argument parentDomain results in improper authentication. Remote exploitation of the attack is possible. The exploit has been made public and could be used. This product follows a rolling release approach for continuous delivery, so version details for affected or updated releases are not provided. The patch is named e3babb5cd83bfe3b99f1d82358ac5c1ea8e8a688. It is recommended to apply a patch to fix this issue. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Vulnerability class: Broken Authentication
Published .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/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
- Jeremyckahn Chitchatter — versions f82538633813c854a81a8b2112a2f6ba17b39cbc
Weakness classification (CWE)
References
- vuldb.com/vuln/427456 (technical-description, vdb-entry)
- vuldb.com/vuln/427456/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-118129 (third-party-advisory)
- vuldb.com/submit/1015027 (third-party-advisory)
- github.com/0xGenesi/CVE/blob/main/Chitchatter_SDK_postMessage_Identity_Key_Inje… (exploit)
- github.com/jeremyckahn/chitchatter/pull/635 (issue-tracking, patch)
- github.com/jeremyckahn/chitchatter/commit/e3babb5cd83bfe3b99f1d82358ac5c1ea8e8a… (patch)
- github.com/jeremyckahn/chitchatter/ (product)
Frequently asked questions
- What is CVE-2026-118129?
- CVE-2026-118129 is a medium-severity vulnerability in Jeremyckahn Chitchatter, classified under Improper Authentication. CVSS score: 6.3/10. Published 2026-10-28.
- How severe is CVE-2026-118129?
- Medium severity. CVSS v3 base score is 6.3 out of 10.