WRITEFREELY · CVE-2026-126498 · Other
NO FIX YET · SEE WHAT TO DO
WriteFreely before 0.17.3 lets an authenticated author inject HTML through a malicious post slug sent to the CreatePost API. The raw slug is placed into a link for paid-shortcode posts, so script runs for RSS and Atom feed readers, newsletter recipients and ActivityPub viewers.
first public Nov 9, 2026 · 1 source
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Self-hosted WriteFreely instances before 0.17.3 where authors can create posts and paid-shortcode posts are used, since the payload reaches readers through feeds, newsletters and ActivityPub. Instances that have only trusted authors or no paid-shortcode posts are at lower risk, but upgrading removes the issue.
Not affected if no-untrusted-authors, version-0.17.3-or-later
Who cares activitypub, rss, self-hosted, writefreely
0.17.3.0.17.3 or later.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.
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This page as .md · .json · 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
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