Stored XSS in @waline/client via the unsanitized markdown preview of a comment's raw body on edit
Affects the waline package up to and including 3.15.2 when a comment is opened for editing. No fixed version is listed in the checked facts.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. A comment is opened for editing, so the editor is seeded with the raw comment body
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
@waline/client, the front-end part of the Waline comment system, has a stored cross-site scripting flaw that an unauthenticated attacker can reach remotely by posting a comment with malicious HTML. The script runs in an administrator's session when that administrator clicks Edit on the comment, letting the attacker act with the administrator's privileges.
Read the original description
Waline is a comment system with backend support. In versions 3.15.2 and prior, @waline/client renders the comment editor's live preview with marked and no sanitizer (utils/markdown.ts), and the preview is injected with v-html. When a comment is edited, the editor is seeded with the comment's raw, un-sanitized body (orig). Only administrators and the comment owner can edit. So an administrator who clicks Edit on an attacker's comment renders that attacker's raw HTML in their own session: an unauthenticated commenter achieves privilege-escalation stored XSS against a moderator with a single Edit click. At time of publication, there are no publicly available patches.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.3/10CVSS 9.3
- No patch5/5No patch listed yet
What would change the score
- Would score about 76 if added to CISA KEV
- Would score about 71 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
A comment is opened for editing, so the editor is seeded with the raw comment bodyWorkaround: The checked facts name no workaround. The described trigger is opening a comment for editing, so that is the feature path the facts identify as the one to watch while no fix exists.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-64670 (Stored XSS in @waline/client via the unsanitized markdown preview of a comment's raw body on edit), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-64670 (entry last updated 2026-11-11): Affected: - walinejs waline: through 3.15.2 Fixed versions: none listed yet. Conditions (all must be true for the bug to be hit): - A comment is opened for editing, so the editor is seeded with the raw comment body (source: https://github.com/walinejs/waline/security/advisories/GHSA-crj3-q72p-ggqm) Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: network access, no login, a user action. CISA KEV: CVE-2026-64670 is not listed as of cve.now's last read. This KEV status is for CVE-2026-64670 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://github.com/walinejs/waline/security/advisories/GHSA-crj3-q72p-ggqm Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-64670 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-64670.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- walinejs waline
through 3.15.2
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-64670
Is CVE-2026-64670 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
When a comment is edited, the editor is loaded with the raw, unsanitized comment body, and its markdown preview displays that content without sanitizing it. Injected script can then run in the administrator's session, read the Waline JWT from localStorage, and take over the administrative account.Source: github.com
Which versions are affected by CVE-2026-64670?
waline: through 3.15.2.Source: cve.now feed data
Am I affected, and how do I check?
Versions up to and including 3.15.2 of waline are listed as affected, and the bug is triggered when a comment is opened for editing. To check an installed copy, compare the waline package version in the project's dependencies against 3.15.2.Source: github.com
How do I fix CVE-2026-64670?
The checked facts list no fixed version, so there is no upgrade target yet. Check the vendor's advisory or release notes for a patched release before relying on any version.Source: github.com
What if there's no patch?
The checked facts name no workaround. The described trigger is opening a comment for editing, so that is the feature path the facts identify as the one to watch while no fix exists.Source: github.com