Svelte affected by XSS in SSR `<option>` element
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-79.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| sveltejs | svelte | 5.39.3 to before 5.51.5 | 5.51.5 | Patch available | CNA |
| — | svelte (npm) | 5.39.3 to before 5.51.5 | 5.51.5 | Patch available | GHSA-h7h7-mm68-gmrc |
- svelte Vendorsveltejs Affected 5.39.3 to before 5.51.5 Fixed in 5.51.5 Patch available CNA
- svelte (npm) Vendor— Affected 5.39.3 to before 5.51.5 Fixed in 5.51.5 Patch available GHSA-h7h7-mm68-gmrc
Remediation
- Fix · CNA svelte (sveltejs) Fixed in 5.51.5
- Fix · GHSA-h7h7-mm68-gmrc svelte (npm) Fixed in 5.51.5 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Build of Podman Desktop - Tech Preview | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27119
- 2026-10-03 Alias added: GHSA-h7h7-mm68-gmrc
References
More sveltejs Svelte vulnerabilities
- TI-2024-30159 Potential mXSS vulnerability due to improper HTML escaping in svelte CVSS 3.1MEDIUM 6.1
- TI-2025-13940 Svelte 5.46.0 - Hydratable Key Script-Breakout XSS (SSR) CVSS 4.0MEDIUM 5.3
- TI-2021-10070 The unofficial Svelte extension before 104.8.0 for Visual Studio Code allows attackers to… CVSS 3.1HIGH 7.8
- TI-2022-09436 Cross-site scripting (XSS) in svelte CVSS 3.1MEDIUM 6.1
- TI-2026-30847 Svelte: ReDoS in `<svelte:element>` Tag Validation CVSS 4.0MEDIUM 5.9
- TI-2026-30853 Svelte: XSS via DOM Clobbering of Internal Framework State CVSS 4.0MEDIUM 5.3
Sources
- CVE-2026-27119 · CVE Program
- CVE-2026-27119 · NVD
- FIRST EPSS
- GHSA-h7h7-mm68-gmrc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-27119 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences