CVE-2026-29049: Chainguard.dev/melange `melange Update-cache` Has Unbounded HTTP Vulnerability

MODERATE
Advisory Identifier: GHSA-7rp8-r62p-q6wc
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CVSS 4.3
CWE-400 CWE-918
Published
Advisory Summary

CVE-2026-29049 is a MODERATE (CVSS 4.3) `melange update-cache` has unbounded http vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Chainguard.dev/melange libraries in the Go ecosystem. The issue involves `melange update-cache` has unbounded http download that can exhaust disk in ci. Remediation is available by upgrading affected packages to version 0.43.4.

CVE-2026-29049 at a Glance

CVE Identifier CVE-2026-29049
GHSA Identifier GHSA-7rp8-r62p-q6wc
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Chainguard.dev/melange
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-29049

To remediate this vulnerability, upgrade all affected Chainguard.dev/melange dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

chainguard.dev/melange fixed: 0.43.4 
Upgrade chainguard.dev/melange to 0.43.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for chainguard.dev/melange

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-29049, inspect your project dependencies for Chainguard.dev/melange:

inspect dependencies for chainguard.dev/melange

Analyze the terminal output to locate any version of Chainguard.dev/melange in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.43.4), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Chainguard.dev/melange, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

`melange update-cache` downloads URIs from build configs via `io.Copy` without any size limit or HTTP client timeout (`pkg/renovate/cache/cache.go`). An attacker-controlled URI in a melange config can cause unbounded disk writes, exhausting disk on the build runner. Affected versions <= 0.40.5. **Fix:** Merged **Acknowledgements** Thank you to Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.

CVE-2026-29049 Affected Chainguard.dev/melange Versions

1 component(s)
Fixed Versions:
0.43.4
Product / Package Ecosystem Affected Versions Fixed Version
chainguard.dev/melange
golang/chainguard.dev/melange
Go
< 0.43.4
0.43.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/chainguard-dev/melange/security/advisories/GHSA-7rp8-r62p-q6wc
NVD — CVE-2026-29049 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-29049
Chainguard.dev/melange Source Repository REPOSITORY
https://github.com/chainguard-dev/melange/pull/2379
Security Fix Commit FIX COMMIT
https://github.com/chainguard-dev/melange/commit/652ca5af08588f78e2d405e64b058fac8398d23f
Chainguard.dev/melange Source Repository REPOSITORY
https://github.com/chainguard-dev/melange
Chainguard.dev/melange Release RELEASE
https://github.com/chainguard-dev/melange/releases/tag/v0.43.4

Frequently Asked Questions

What is CVE-2026-29049?
CVE-2026-29049 is a security vulnerability in Chainguard.dev/melange involving `melange update-cache` has unbounded HTTP download that can exhaust disk in CI under CWE-400: Uncontrolled Resource Consumption.
Which Chainguard.dev/melange versions are affected?
Affected versions include releases prior to 0.43.4 across affected packages: chainguard.dev/melange.
What version fixes CVE-2026-29049?
Upgrading to 0.43.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is chainguard.dev/melange affected?
Yes, chainguard.dev/melange is affected in releases prior to 0.43.4. Upgrade your dependency to 0.43.4 or later.
What is the CVSS score of CVE-2026-29049?
CVE-2026-29049 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-29049?
CVE-2026-29049 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check Go dependencies for CVE-2026-29049?
Run the dependency tree command: 'inspect dependencies for chainguard.dev/melange'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7rp8-r62p-q6wc",
  "modified" : "2026-07-07T13:10:50Z",
  "published" : "2026-03-02T22:04:23Z",
  "aliases" : [ "CVE-2026-29049" ],
  "summary" : "`melange update-cache` has unbounded HTTP download that can exhaust disk in CI",
  "details" : "`melange update-cache` downloads URIs from build configs via `io.Copy` without any size limit or HTTP client timeout (`pkg/renovate/cache/cache.go`). An attacker-controlled URI in a melange config can cause unbounded disk writes, exhausting disk on the build runner. Affected versions <= 0.40.5.\n\n**Fix:** Merged\n**Acknowledgements**\n\nThank you to Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "chainguard.dev/melange"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.43.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/melange/security/advisories/GHSA-7rp8-r62p-q6wc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-29049"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/melange/pull/2379"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/melange/commit/652ca5af08588f78e2d405e64b058fac8398d23f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/chainguard-dev/melange"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/melange/releases/tag/v0.43.4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-02T22:04:23Z",
    "nvd_published_at" : "2026-03-06T07:16:02Z"
  }
}