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TI-2026-81580 Aliases CVE-2026-118129GHSA-4rhf-9gx6-4pqp

Improper authentication in Chitchatter PostMessage handler

Priority MEDIUM 57CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · Low
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-287.

Summary

Chitchatter up to commit f82538633813c854a81a8b2112a2f6ba17b39cbc has improper authentication in the isConfigMessageEvent function of src/Bootstrap.tsx, which handles PostMessage events (CWE-287). Manipulating the parentDomain argument lets a remote attacker get past the authentication check, and user interaction is required. A public exploit has been released and is linked in the references.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00343 28th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
jeremyckahnChitchatterf82538633813c854a81a8b2112a2f6ba17b39cbc—No fix listedCNA
  • Chitchatter Vendorjeremyckahn Affected f82538633813c854a81a8b2112a2f6ba17b39cbc Fixed in — No fix listed CNA

CPE names CNA · 1

CPEVersionsRoleVendor
cpe:2.3:a:jeremyckahn:chitchatter:*:*:*:*:*:*:*:*——jeremyckahn
  • cpe:2.3:a:jeremyckahn:chitchatter:*:*:*:*:*:*:*:* Versions — — ·jeremyckahn

Remediation

Apply patch e3babb5cd83bfe3b99f1d82358ac5c1ea8e8a688 to Chitchatter. The sources list no fixed version for Chitchatter.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-118129
  2. 2026-10-28 Alias added: GHSA-4rhf-9gx6-4pqp
  3. 2026-11-02 CISA SSVC decision points changed
  4. 2026-11-02 Priority changed: LOW → MEDIUM

References

Exploit 1

Patch 2

Other 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences