CVE-2023-48703 — go-saml
HIGHCVE-2023-48703 is a high-severity (CVSS 7.5) Improper Authentication vulnerability in github.com/RobotsAndPencils/go-saml. No vendor fix is recorded yet; mitigation options are listed below.
RobotsAndPencils go-saml authentication bypass vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-48703.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-48703 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/RobotsAndPencils/go-samlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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 tested before it can be used.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/RobotsAndPencils/go-saml | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/RobotsAndPencils/go-saml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of github.com/RobotsAndPencils/go-saml has shipped for CVE-2023-48703 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-48703 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-48703. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-48703 in your dependencies?
O3 Security finds CVE-2023-48703 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.