Vulnerability in @sveltejs/kit (CVE-2026-66062)
Summary
Vulnerability in @sveltejs/kit (CVE-2026-66062). Risk of unauthorized operations or information disclosure. Exploitable via Accept. Mitigation: upgrade to 2.70.2 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-66062 has been found in @sveltejs/kit.
Attackers can target a specific entry point like Accept over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade @sveltejs/kit to 2.70.2 or later.
If unsure, ask your IT team or search "@sveltejs/kit CVE-2026-66062" on the vendor's site.
CVE-2026-66062 (@sveltejs/kit) — CWE-1333 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Accept
Patched: 2.70.2 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-1333) exists in @sveltejs/kit. Attackers reach the vulnerable code path via Accept without authentication.
Check the vendor advisory for the affected versions of @sveltejs/kit. Attack surface: Accept.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 2.70.2.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@sveltejs/kit' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r '@sveltejs/kit' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@sveltejs/kitを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @sveltejs/kit to 2.70.2ステージング環境で 2.70.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com