RobotsAndPencils go-saml authentication bypass vulnerability

Exploitation

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

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2023-48703: 0.56% estimated exploitation activity in the next 30 days; percentile 46.62 (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.

RobotsAndPencils go-saml, a SAML client library written in Go, contains an authentication bypass vulnerability in all known versions. This is due to how the xmlsec1 command line tool is called internally to verify the signature of SAML assertions. When xmlsec1 is used without defining the enabled key data, the origin of the public key for the signature verification is, unfortunately, not restricted. That means an attacker can sign the SAML assertions themselves and provide the required public key (e.g. an RSA key) directly embedded in the SAML token. Projects still using RobotsAndPencils/go-saml should move to another SAML library or alternatively remove support for SAML from their projects. The vulnerability can likely temporarily be fixed by forking the go-saml project and adding the command line argument --enabled-key-data and specifying a value such as x509 or raw-x509-cert when calling the xmlsec1 binary in the verify function. Please note that this workaround must be carefully…

Published by the source

5 Aug 2024, 21:29 UTC

Last modified by the source

5 Aug 2024, 21:29 UTC

Source last checked

26 Oct 2026, 15:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6h53-q94j-348w

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# Patch Next advisory brief: CVE-2023-48703

Advisory: RobotsAndPencils go-saml authentication bypass vulnerability
IDs: CVE-2023-48703, GHSA-6h53-q94j-348w
Record: https://patchnext.com/advisories/cve-2023-48703 (revision 1, source checked 26 Oct 2026, 15:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/RobotsAndPencils/go-saml: affected <= 0.0.0-20230606195814-29020529affc

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/RobotsAndPencils/go-saml.
- 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-6h53-q94j-348w (GitHub-reviewed advisory GHSA-6h53-q94j-348w lists affected ranges: Go github.com/RobotsAndPencils/go-saml >=0 <=0.0.0-20230606195814-29020529affc)

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