CVE-2026-48702

Description

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 this vulnerability since the check is applied after decompression.

CVSS Metrics

• v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.32%• Percentile: 26%

Techniques & Countermeasures

• CWE-770•Allocation of Resources Without Limits or Throttling

  The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

Affected Systems

• chainguard•aactl

  < 0.4.12-r60

• chainguard•chainctl-fips

  < 0.2.292-r1

• chainguard•cloudbeat-8.17

  < 8.17.10-r31

• chainguard•cloudbeat-9.0

  < 9.0.8-r33

• chainguard•cloudbeat-9.1

  < 9.1.10-r23

• chainguard•cloudbeat-9.2

  < 9.2.8-r12

• chainguard•cloudbeat-9.4

  < 9.4.2-r5

• chainguard•cloudbeat-fips-8.17

  < 8.17.10-r37

• chainguard•cloudbeat-fips-9.0

  < 9.0.8-r37

• chainguard•cloudbeat-fips-9.1

  < 9.1.10-r29

• chainguard•cloudbeat-fips-9.2

  < 9.2.8-r12

• chainguard•cloudbeat-fips-9.4

  < 9.4.2-r6

• chainguard•commercial-chainloop-backend

  all

• chainguard•commercial-chainloop-cli

  all

• chainguard•commercial-kyverno-1.13

  all

• chainguard•commercial-kyverno-1.14

  all

• chainguard•commercial-kyverno-1.15

  all

• chainguard•commercial-kyverno-1.16

  all

• chainguard•commercial-kyverno-1.17

  all

• chainguard•commercial-kyverno-background-controller-1.13

  all

• chainguard•commercial-kyverno-background-controller-1.14

  all

• chainguard•commercial-kyverno-background-controller-1.15

  all

• chainguard•commercial-kyverno-background-controller-1.16

  all

• chainguard•commercial-kyverno-background-controller-1.17

  all

• chainguard•commercial-kyverno-cleanup-controller-1.13

  all

• chainguard•commercial-kyverno-cleanup-controller-1.14

  all

• chainguard•commercial-kyverno-cleanup-controller-1.15

  all

• chainguard•commercial-kyverno-cleanup-controller-1.16

  all

• chainguard•commercial-kyverno-cleanup-controller-1.17

  all

• chainguard•commercial-kyverno-reports-controller-1.13

  all

• chainguard•commercial-kyverno-reports-controller-1.14

  all

• chainguard•commercial-kyverno-reports-controller-1.15

  all

• chainguard•commercial-kyverno-reports-controller-1.16

  all

• chainguard•commercial-kyverno-reports-controller-1.17

  all

• chainguard•commercial-kyvernopre-1.13

  all

• chainguard•commercial-kyvernopre-1.14

  all

• chainguard•commercial-kyvernopre-1.15

  all

• chainguard•commercial-kyvernopre-1.16

  all

• chainguard•commercial-kyvernopre-1.17

  all

• chainguard•crossplane-1.20

  < 1.20.10-r4

• chainguard•crossplane-2.0

  < 2.0.8-r8

• chainguard•crossplane-2.1

  < 2.1.7-r2

• chainguard•crossplane-2.2

  < 2.2.3-r2

• chainguard•crossplane-2.3

  < 2.3.3-r2

• chainguard•crossplane-2.3-crank

  < 2.3.3-r2

• chainguard•crossplane-fips-1.20

  < 1.20.10-r2

• chainguard•crossplane-fips-2.0

  < 2.0.8-r8

• chainguard•crossplane-fips-2.1

  < 2.1.7-r2

• chainguard•crossplane-fips-2.2

  < 2.2.3-r2

• chainguard•crossplane-fips-2.3

  < 2.3.3-r2

Showing first 50 affected entries in server-rendered view.

References (8)

• https://github.com/sigstore/rekor/security/advisories/GHSA-47q9-m4ww-924m
• https://github.com/sigstore/rekor
• https://ubuntu.com/security/CVE-2026-48702
• https://www.cve.org/CVERecord?id=CVE-2026-48702
• https://github.com/sigstore/rekor/pull/2831
• https://security-tracker.debian.org/tracker/CVE-2026-48702
• https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48702.json
• https://nvd.nist.gov/vuln/detail/CVE-2026-48702