Moov signedxml: Unauthenticated denial of service in exclusive XML canonicalization

Exploitation

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

CVSS

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

EPSS

• CVE-2026-113729: 0.46% estimated exploitation activity in the next 30 days; percentile 39.81 (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.

Exclusive XML canonicalization (http://www.w3.org/2001/10/xml-exc-c14n#) in github.com/moov-io/signedxml copied the entire accumulated namespace map at every node during ValidateReferences(), before any reference digest or signature check. For a chain of nested elements that each declare many unused namespace prefixes, that produced O(m × depth²) time and peak memory (m = prefixes per level). beevik/etree caps tree depth (~1024), but m is unbounded, so a small attacker-controlled document (on the order of 1 MB) could drive multi-gigabyte allocations and OOM the process. No valid signature, matching certificate, or authentication is required. This is the library’s core path for SAML / WS-Federation service providers, which canonicalize attacker-supplied XML prior to authentication. Affected - Package: github.com/moov-io/signedxml - Function: ExclusiveCanonicalization (exclusivecanonicalization.go) - Verified: v1.4.0 and current default branch (commit d79064a). Earlier v1.2.x–v1.3.x…

Published by the source

21 Oct 2026, 16:27 UTC

Last modified by the source

21 Oct 2026, 16:45 UTC

Source last checked

26 Oct 2026, 15:32 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-5588-rp99-5fjh

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-5588-rp99-5fjh

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# Patch Next advisory brief: CVE-2026-113729

Advisory: Moov signedxml: Unauthenticated denial of service in exclusive XML canonicalization
IDs: CVE-2026-113729, GHSA-5588-rp99-5fjh
Record: https://patchnext.com/advisories/cve-2026-113729 (revision 2, source checked 26 Oct 2026, 15:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/moov-io/signedxml 1.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/moov-io/signedxml: affected <= 1.4.0; fixed in 1.4.1

## Suggested inspection (read-only)
- Go github.com/moov-io/signedxml: 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/moov-io/signedxml.
- 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://osv.dev/vulnerability/GHSA-5588-rp99-5fjh (OSV record GHSA-5588-rp99-5fjh lists affected ranges: Go github.com/moov-io/signedxml >=0 <1.4.1 (fixed))
- Verified: https://github.com/advisories/GHSA-5588-rp99-5fjh (GitHub-reviewed advisory GHSA-5588-rp99-5fjh lists affected ranges: Go github.com/moov-io/signedxml >=0 <=1.4.0)

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