Security readout for executives and security teams
Plain-English summary
TinyMCE before 5.9.0 could allow a remote unauthenticated attacker to store malicious HTML that runs JavaScript when another user views it. Business impact is mainly browser-session compromise, data exposure within the application, and unauthorized actions as the viewing user.
Executive priority
Treat this as a medium-priority web application risk. Escalate if TinyMCE is used in public submission portals, CMS workflows, support queues, or admin review panels where stored attacker content reaches privileged users.
Technical view
This is a stored cross-site scripting issue in TinyMCE, tracked as CWE-79 with CVSS 6.1. The CVSS vector indicates network access, low complexity, no privileges, required user interaction, changed scope, and low confidentiality and integrity impact.
Likely exposure
Exposure is likely in web applications embedding TinyMCE versions before 5.9.0, especially where untrusted or unauthenticated users can submit content that other users later view or edit.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires crafted HTML to be stored and later rendered to another user, so impact depends on application workflow and viewer privileges.
Researcher notes
The source bundle has imprecise affected metadata, but the narrative and advisories consistently identify TinyMCE before 5.9.0. No exploit details or active exploitation evidence are provided. Validate exposure by version and by stored-content workflow.
Mitigation direction
- Upgrade TinyMCE to version 5.9.0 or later.
- Review the TinyMCE advisory and 5.9 release security notes.
- Inventory embedded, bundled, and transitive TinyMCE copies.
- Restrict untrusted content submission paths until upgraded.
- Prioritize apps where admins review public submissions.
Validation and detection
- Check package manifests and lockfiles for TinyMCE below 5.9.0.
- Confirm deployed static assets report TinyMCE 5.9.0 or later.
- Identify forms where unauthenticated users can create editor content.
- Review whether stored content is viewed by privileged users.
- Retest affected workflows after upgrade without using live exploit payloads.
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-2024-21908 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
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.
SSVC decision data
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:L/I:L/A:N2.82.7CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/tinymce/tinymce/security/advisories/GHSA-5h9g-x5rv-25wgCVE reference, VulnCheck · vendor-advisory
- https://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixesCVE reference, VulnCheck · related
- https://github.com/advisories/GHSA-5h9g-x5rv-25wgCVE reference, VulnCheck · vendor-advisory
- https://vulncheck.com/advisories/vc-advisory-GHSA-5h9g-x5rv-25wgCVE reference, VulnCheck · third-party-advisory
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.