CVE
Astro cross-site scripting in Solid.js renderer
- Exploited
- No known exploitation
- Fix
- Fixed in 7.1.2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 7.1.2.
- 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
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.38% · 32nd percentile
- 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? →
- 19/100 · provisional
- 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
Astro, a web framework, has a cross-site scripting flaw in its Solid.js renderer (@astrojs/solid-js) that lets an attacker inject active HTML through a crafted slot name in a request. The bug can be reached remotely without logging in, but it needs a victim to take an action, and it only applies when a hydrated Solid component dynamically reads the attacker-chosen slot.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Astro is a web framework for content-driven websites. From 0.2.0 until 7.1.2, the @astrojs/solid-js renderer inserted a named slot into the quoted name attribute of an astro-slot wrapper without HTML escaping. A request-controlled slot name containing a quote could terminate the attribute and inject active HTML. Exploitation required a hydrated Solid component using a client:* directive and dynamic access to the attacker-chosen slot property; a component that did not render that slot emitted only escaped fallback content. This issue is fixed in version 7.1.2.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure7/25Reachable over the network without a login · Unknown: No advisory context yet
- Reach10/20Affects npm packages
- Severity2.3/10CVSS 2.3
- No patch0/5No signal
What would change the score
- Would score about 74 if added to CISA KEV
- Would score about 69 if CISA's SSVC rates exploitation active
- Would score about 34 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 7.1.2.
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-2026-126363 (Astro: Reflected XSS via unescaped slot names in @astrojs/solid-js), 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-2026-126363 (entry last updated 2026-11-12):
Affected:
- withastro astro: from 0.2.0, fixed in 7.1.2
- npm package @astrojs/solid-js: from 0.2.0, fixed in 7.1.2
Fixed versions: 7.1.2.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-126363 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126363 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Packages (npm): find every lockfile in each project and run the stack.check operation of the cve.now MCP server (execute) on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.
- 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/withastro/astro/security/advisories/GHSA-jmv2-qgxf-f995
- https://github.com/withastro/astro/commit/290b196ddb48de11783ff128e2b7272c61490a20
- https://github.com/withastro/astro/releases/tag/@astrojs/solid-js@7.1.2
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-2026-126363
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-126363"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- withastro astro
From 0.2.0 · fixed in 7.1.2
From 0.2.0 · fixed in 7.1.2
Evidence 5
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 2
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-126363
Is CVE-2026-126363 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
Which versions are affected by CVE-2026-126363?
astro: from 0.2.0 before 7.1.2. @astrojs/solid-js (npm): from 0.2.0 before 7.1.2.Source: cve.now feed data
How do I fix CVE-2026-126363?
Upgrade to a fixed version: 7.1.2.Source: cve.now feed data