How severe is GHSA-27mw-82g8-phjj?

GHSA-27mw-82g8-phjj has a CVSS score of 0/10, rated NONE. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-27mw-82g8-phjj?

GHSA-27mw-82g8-phjj affects the following packages: @sveltejs/kit (npm). Ecosystems affected: npm.

How do I fix GHSA-27mw-82g8-phjj?

Update @sveltejs/kit to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-27mw-82g8-phjj is resolved across your whole dependency graph.

How do I detect GHSA-27mw-82g8-phjj in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/kit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-27mw-82g8-phjj if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-27mw-82g8-phjj actively exploited in the wild?

No public exploit code has been indexed for GHSA-27mw-82g8-phjj yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-27mw-82g8-phjj?

GHSA-27mw-82g8-phjj has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 7th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-27mw-82g8-phjj?

GHSA-27mw-82g8-phjj is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-27mw-82g8-phjj published, and has it been updated?

GHSA-27mw-82g8-phjj was published on October 23, 2026 and was last updated on October 23, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

NONE severity

SvelteKit : XSS via untrusted cache-control header in prerendered pageGHSA-27mw-82g8-phjj

NONEFix: sveltejs/kit@d9d55b5

GHSA-27mw-82g8-phjj is a none-severity (CVSS 0) Cross-site Scripting (XSS) vulnerability in @sveltejs/kit. A fix is available for @sveltejs/kit — see the affected versions and patch details below.

Also known asCVE-2026-114061

Published

Oct 23, 2026

Updated

Oct 23, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 23, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-27mw-82g8-phjj by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

📦@sveltejs/kit

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Applications that prerender pages and use setHeaders to set a cache-control header from an untrusted source are vulnerable to cross-site scripting (XSS).

SvelteKit inserts the header value into a <meta http-equiv="cache-control"> tag without escaping it. An attacker who can influence this value at prerender time can break out of the content attribute and inject HTML or JavaScript into the generated page. The injected code can then execute when users visit the page.

Patches

The fix escapes the header value before inserting it into the generated HTML. Upgrade to @sveltejs/kit version 3.0.0 or later.

Workarounds

Avoid forwarding untrusted cache-control header values with setHeaders on prerendered pages. Use a fixed, trusted cache policy instead.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@sveltejs/kit`	all versions	3.0.0`npm install @sveltejs/kit@3.0.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @sveltejs/kit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @sveltejs/kit to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-27mw-82g8-phjj is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact Applications that prerender pages and use `setHeaders` to set a `cache-control` header from an untrusted source are vulnerable to cross-site scripting (XSS). SvelteKit inserts the header value into a `<meta http-equiv="cache-control">` tag without escaping it. An attacker who can influence this value at prerender time can break out of the `content` attribute and inject HTML or JavaScript into the generated page. The injected code can then execute when users visit the page. ### Patches The fix escapes the header value before inserting it into the generated HTML. Upgrade to `@svel

O3 Security · Impact-Aware SCA

Is GHSA-27mw-82g8-phjj in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works