Quill has unbounded memory allocation via unvalidated size fields in Mach-O binary parsing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.5 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-31961: 0.10% estimated exploitation activity in the next 30 days; percentile 1.03 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Quill before version v0.7.1 contains an unbounded memory allocation vulnerability when parsing Mach-O binaries. Exploitation requires that Quill processes an attacker-supplied Mach-O binary, which is most likely in environments such as CI/CD pipelines, shared signing services, or any workflow where externally-submitted binaries are accepted for signing. When parsing a Mach-O binary, Quill reads several size and count fields from the LCCODESIGNATURE load command and embedded code signing structures (SuperBlob, BlobIndex) and uses them to allocate memory buffers without validating that the values are reasonable or consistent with the actual file size. Affected fields include DataSize, DataOffset, and Size from the load command, Count from the SuperBlob header, and Length from individual blob headers. An attacker can craft a minimal (~4KB) malicious Mach-O binary with extremely large values in these fields, causing Quill to attempt to allocate excessive memory. This leads to…

Published by the source

11 Mar 2026, 00:38 UTC

Last modified by the source

13 Apr 2026, 12:12 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xj69-m9qq-8m94

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# Patch Next advisory brief: CVE-2026-31961

Advisory: Quill has unbounded memory allocation via unvalidated size fields in Mach-O binary parsing
IDs: CVE-2026-31961, GHSA-xj69-m9qq-8m94
Record: https://patchnext.com/advisories/cve-2026-31961 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/anchore/quill 0.7.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/anchore/quill: affected < 0.7.1; fixed in 0.7.1

## Suggested inspection (read-only)
- Go github.com/anchore/quill: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/anchore/quill.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xj69-m9qq-8m94 (GitHub-reviewed advisory GHSA-xj69-m9qq-8m94 lists affected ranges: Go github.com/anchore/quill >=0 <0.7.1)

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