Vulnerability in @sigstore/core (CVE-2026-48758)
Summary
Vulnerability in @sigstore/core (CVE-2026-48758). Risk of unauthorized operations or information disclosure. Exploitable via preAuthEncoding. Mitigation: upgrade to 3.2.1 or later.
Original description
The description as published by the source.
sigstore-js provides JavaScript libraries for interacting with Sigstore services. Prior to 3.2.1, the preAuthEncoding function in @sigstore/core uses Node.js ascii encoding when converting the PAE string to bytes, allowing payloadType to be mutated after signing without invalidating the signature and breaking the type-binding guarantee that DSSE is designed to provide. This issue is fixed in version 3.2.1.
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-2026-48758 has been found in @sigstore/core.
Attackers can target a specific entry point like preAuthEncoding over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade @sigstore/core to 3.2.1 or later.
If unsure, ask your IT team or search "@sigstore/core CVE-2026-48758" on the vendor's site.
CVE-2026-48758 (@sigstore/core) — CWE-347 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Attack surface: preAuthEncoding / payloadType / payloadType.length
Patched: 3.2.1 — 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-347) exists in @sigstore/core. Attackers reach the vulnerable code path via preAuthEncoding.
Check the vendor advisory for the affected versions of @sigstore/core. Attack surface: preAuthEncoding / payloadType / payloadType.length.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 3.2.1.
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 '@sigstore/core' . 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 '@sigstore/core' . | 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
@sigstore/core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 @sigstore/core to 3.2.1ステージング環境で 3.2.1 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
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com