Vulnerability in github.com/sigstore/rekor (CVE-2026-48702)
Summary
Vulnerability in github.com/sigstore/rekor (CVE-2026-48702). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1.5.2 or later.
Original description
The description as published by the source.
Rekor is a software supply chain transparency log. Starting in version 0.3.0 and prior to version 1.5.2, the Package.Unmarshal() function in pkg/types/alpine/apk.go decompresses the signature and control gzip members of an APK file into in-memory buffers without bounding the total decompressed size. The existing max_apk_metadata_size check (default 1MB) is only applied to individual tar entry header sizes after decompression completes, so it does not prevent a decompression bomb from consuming unbounded heap memory. An attacker can craft a gzip stream that compresses at a ~1000:1 ratio (e.g., 2MB compressed zeros → 2GB decompressed). When submitted as spec.package.content in an Alpine ProposedEntry, the server decompresses the full payload into memory during request processing, triggering a fatal Go runtime out-of-memory error or OS OOM-kill that cannot be caught by the server's recover() middleware. This is reachable via two unauthenticated endpoints, POST /api/v1/log/entries (createLogEntry) and POST /api/v1/log/entries/retrieve (searchLogQuery). Both invoke V001Entry.Canonicalize() → fetchExternalEntities() → apk.Unmarshal(packageData), which performs the unbounded decompression. Version 1.5.2 patches the issue. There is no effective workaround. Setting max_request_body_size reduces but does not eliminate exposure due to the ~1000:1 compression ratio (a 1MB body limit still allows ~1GB heap allocation). Setting max_apk_metadata_size has no effect on t…
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-2026-48702 has been found in github.com/sigstore/rekor.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade github.com/sigstore/rekor to 1.5.2 or later.
If unsure, ask your IT team or search "github.com/sigstore/rekor CVE-2026-48702" on the vendor's site.
CVE-2026-48702 (github.com/sigstore/rekor) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.5.2 — 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-770) exists in github.com/sigstore/rekor.
Check the vendor advisory for the affected versions of github.com/sigstore/rekor.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 1.5.2.
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 'github.com/sigstore/rekor' . 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
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1Identify exposure identify
grep -r 'github.com/sigstore/rekor' . | 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
github.com/sigstore/rekor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 github.com/sigstore/rekor to 1.5.2ステージング環境で 1.5.2 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。
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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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-48702 rekor
- Ubuntu UBUNTU-CVE-2026-48702 rekor
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com