CVE-2025-24981
In affected versions unsafe parsing logic of the URL from markdown can lead to arbitrary JavaScript code due to a bypass to the existing guards around the `javascript:` protocol scheme in the URL.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
MDC is a tool to take regular Markdown and write documents interacting deeply with a Vue component. In affected versions unsafe parsing logic of the URL from markdown can lead to arbitrary JavaScript code due to a bypass to the existing guards around the `javascript:` protocol scheme in the URL. The parsing logic implement in `props.ts` maintains a deny-list approach to filtering potential malicious payload. It does so by matching protocol schemes like `javascript:` and others. These security guards can be bypassed by an adversarial that provides JavaScript URLs with HTML entities encoded via hex string. Users who consume this library and perform markdown parsing from unvalidated sources could result in rendering vulnerable XSS anchor links. This vulnerability has been addressed in version 0.13.3 and all users are advised to upgrade. There are no known workarounds for this vulnerability.
- CVSS 3.1
- 9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L
- EPSS
- 0.68% probability · 51th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.