CVE-2026-126498
WriteFreely before 0.17.3 Stored XSS via Unsanitized Post Slug
WriteFreely before 0.17.3 contains a stored cross-site scripting vulnerability that allows authenticated authors to inject HTML by supplying a malicious post slug via the CreatePost API. The raw slug is concatenated into an anchor by augmentReadingDestination() for paid-shortcode posts, executing script for RSS/Atom feed readers, newsletter recipients and ActivityPub viewers.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| WriteFreely Musing Studio github.com/writefreely/writefreely
golang |
≥ 0; < 0.17.3 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 5.1 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N | CNA: VulnCheck |
| 3.1 / 5.4 medium |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N | CNA: VulnCheck |
| 4.0 / 5.1 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 5.4 medium |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/writefreely/writefreely/security/advisories/GHSA-cwxm-8ch5-j2vhCNA: VulnCheck · vendor-advisory
- https://github.com/writefreely/writefreely/commit/d7231d81a914f1314a218d5e8fde6e0341391ccdCNA: VulnCheck · patch
- https://github.com/writefreely/writefreely/releases/tag/v0.17.3CNA: VulnCheck · release-notes
- https://github.com/writefreely/writefreely/blob/v0.17.2/postrender.go#L117-L121CNA: VulnCheck · technical-description
- https://github.com/writefreely/writefreely/blob/v0.17.2/database.go#L702-L705CNA: VulnCheck · technical-description
- https://www.vulncheck.com/advisories/writefreely-before-0.17.3-stored-xss-via-unsanitized-post-slugCNA: VulnCheck · third-party-advisory
- https://github.com/writefreely/writefreely/blob/v0.17.2/database.go#L702-L705[email protected]
- https://github.com/writefreely/writefreely/blob/v0.17.2/postrender.go#L117-L121[email protected]
- https://github.com/writefreely/writefreely/commit/d7231d81a914f1314a218d5e8fde6e0341391ccd[email protected]
- https://github.com/writefreely/writefreely/releases/tag/v0.17.3[email protected]
- https://github.com/writefreely/writefreely/security/advisories/GHSA-cwxm-8ch5-j2vh[email protected]
- https://www.vulncheck.com/advisories/writefreely-before-0.17.3-stored-xss-via-unsanitized-post-slug[email protected]
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