SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header
Impact
SvelteKit is vulnerable to remote CPU-exhaustion DoS attacks via specifically-crafted Accept headers. The impact is mitigated by default header length limits on most platforms, but in the case of raised or absent limits a denial of service is possible.
Patches
The vulnerability is patched in @sveltejs/kit version 2.70.2.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @sveltejs/kit | < 2.70.2 | 2.70.2 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- Weakness (CWE)
CWE-1333- Platform
- npm
- Package
@sveltejs/kit- Disclosed
- 07.08.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-29g2-3rmr-qm68 - CC BY 4.0
Vulnerability history: @sveltejs/kit
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 17
- First → latest
- 04.2023 08.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 6
- Medium 8
- Low 3
Disclosures per year
- 2023: 2
- 2024: 3
- 2025: 1
- 2026: 11
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SvelteKit: ReDoS (O(n^2)) in content negotiation — unauthenticated DoS via the Accept header this entry
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