---
id: CVE-2026-48702
title: Rekor is a software supply chain transparency log
summary: >-
  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 i…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: Red Hat
product: Red Hat Hardened Images
affected:
  - multicluster_engine_for_kubernetes
  - trusted_artifact_signer
  - hardened_images
  - trusted_artifact_signer 1.3
  - trusted_artifact_signer 1.4
patched:
  - hardened_images
  - trusted_artifact_signer 1.3
  - trusted_artifact_signer 1.4
published: '2026-08-13'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T20:05:53.723'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48702'
references:
  - url: 'https://github.com/sigstore/rekor/security/advisories/GHSA-47q9-m4ww-924m'
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48702.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-48702'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2499685'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-48702'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48702'
  - url: 'https://access.redhat.com/errata/RHSA-2026:25138'
  - url: 'https://access.redhat.com/errata/RHSA-2026:35111'
  - url: 'https://access.redhat.com/errata/RHSA-2026:59439'
  - url: 'https://access.redhat.com/errata/RHSA-2026:50873'
  - url: 'https://github.com/sigstore/rekor'
  - url: 'https://github.com/advisories/GHSA-47q9-m4ww-924m'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - osv
  - go
  - ghsa
epss: 0.00324
epssPercentile: 0.25744
aliases:
  - GHSA-47q9-m4ww-924m
  - GO-2026-5778
ecosystem: go
ingestedAt: '2026-06-26T16:43:14.218Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-48702)

Affected packages:

- `github.com/sigstore/rekor >= 0.3.0, < 1.5.2`

Patched in:

- `github.com/sigstore/rekor 1.5.2`

Source: https://osv.dev/vulnerability/GHSA-47q9-m4ww-924m

## Vendor advisories

- **RHSA-2026:25138** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25138)
- **RHSA-2026:35111** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:35111)
- **RHSA-2026:59439** · Red Hat · fixed in: Red Hat Trusted Artifact Signer 1.3 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59439)
- **RHSA-2026:50873** · Red Hat · fixed in: Red Hat Trusted Artifact Signer 1.4 · released 2026-08-05 · [advisory](https://access.redhat.com/errata/RHSA-2026:50873)
- **Red Hat VEX** · Important · affected: Multicluster Engine for Kubernetes, Red Hat Trusted Artifact Signer · no fix planned: Multicluster Engine for Kubernetes, Red Hat Trusted Artifact Signer · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48702.json)