CVE-2026-27119 Svelte affected by XSS in SSR `<option>` element
Attackers can inject HTML via unescaped SSR option elements, potentially leading to code execution in server-rendered applications.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-27119?
CVE-2026-27119 is a medium-severity cross-site scripting vulnerability in sveltejs svelte, published on 20 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
svelte performance oriented web framework. From 5.39.3, <=5.51.4, in certain circumstances, the server-side rendering output of an <option> element does not properly escape its content, potentially allowing HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.
Weakness: CWE-79
Which versions are affected by CVE-2026-27119?
2 open source packages ship an affected version, including svelte. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
svelte npm | From 5.39.3 | 5.51.5 |
svelte npm | From 5.39.3 | 5.51.5 |
Products include Svelte Svelte.
How do I fix CVE-2026-27119?
Upgrade svelte to 5.51.5 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-27119 being exploited?
There is no known exploitation of CVE-2026-27119 in the wild and no public exploit code.
Other vulnerabilities in sveltejs svelte
- CVE-2021-29261 Code injection in n/a
- CVE-2026-42567 Svelte: ReDoS in `<svelte:element>` Tag Validation
- CVE-2024-45047 Potential mXSS vulnerability due to improper HTML escaping in svelte
- CVE-2022-25875 Cross-site Scripting (XSS)
- CVE-2026-42573 Svelte: XSS via DOM Clobbering of Internal Framework State
Sources
Also known as GHSA-h7h7-mm68-gmrc.