Security readout for executives and security teams
Plain-English summary
ChatterMate versions before 1.0.9 can store and run unsafe browser content submitted through chatbot input. If a user views the affected chat content, an attacker may access client-side data such as tokens or cookies. This is serious where ChatterMate is exposed to untrusted users or handles authenticated sessions.
Executive priority
Treat this as a priority remediation for any customer-facing or authenticated ChatterMate deployment. The business risk is account or session compromise through the browser, not server takeover. Patch promptly and validate exposure before assuming compromise.
Technical view
CVE-2026-24399 is a stored XSS issue in chattermate.chat before 1.0.9. Chat input is not safely handled, allowing malicious HTML/JavaScript to execute in a viewer’s browser context. The advisory rates it CVSS 9.3, with network attack vector, low complexity, no privileges required, and user interaction required.
Likely exposure
Highest exposure is for internet-facing ChatterMate deployments, public chatbot interfaces, and environments where chat content is viewed by authenticated staff or customers. Systems on version 1.0.8 or below are affected according to the source bundle.
Exploitation context
The provided sources do not state active exploitation, and KEV status is false. Exploitation requires a victim to view or interact with stored malicious chat content. Impact can include theft of browser-accessible session data and actions performed in the victim’s browser context.
Researcher notes
The public record identifies CWE-79 stored XSS in chattermate.chat below 1.0.9 and links the fixing commit and release. Evidence is sufficient for affected-version triage and remediation direction, but the provided sources do not confirm exploitation in the wild.
Mitigation direction
- Upgrade chattermate.chat to version 1.0.9 or later.
- Review the GitHub advisory and release notes for vendor-specific guidance.
- Restrict untrusted access to chatbot interfaces until upgraded.
- Review existing chatbot content for suspicious embedded HTML or script-like content.
- Consider clearing exposed sessions or tokens if compromise is suspected.
Validation and detection
- Inventory all ChatterMate deployments and identify their running versions.
- Confirm whether any deployment is version 1.0.8 or below.
- Verify the 1.0.9 release or later is installed after remediation.
- Review application logs for unusual chatbot input around the exposure window.
- Validate that stored chat content is safely rendered after upgrade.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-24399 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N2.85.8Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.3CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/chattermate/chattermate.chat/security/advisories/GHSA-72p3-w95w-q3j4CVE reference · x_refsource_CONFIRM
- https://github.com/chattermate/chattermate.chat/commit/ff3398031abb97ae28546eaf993fed3619eaffddCVE reference · x_refsource_MISC
- https://github.com/chattermate/chattermate.chat/releases/tag/v1.0.9CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.