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Fencer Vulns
no cvss —

GO-2026-6909 json

Nil-pointer panic in validateAssertion and namespace-blind Subject.NameID in github.com/crewjam/saml

published 2026-11-05 3 d ago modified 2026-11-05 3 d ago

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

github.com/crewjam/saml through v0.5.1 contains two vulnerabilities in SAML assertion processing:

1. ServiceProvider.validateAssertion dereferences assertion.Issuer without a nil check when ExpectedIDPEntityID is non-empty. A signed SAML assertion that omits the optional <saml:Issuer> element causes a nil-pointer dereference panic after signature verification.

2. Subject uses the bare XML struct tag xml:"NameID", which matches <NameID> elements in any XML namespace. When a signed assertion omits <saml:NameID> and includes a <NameID> element in a foreign namespace inside <saml:Subject>, encoding/xml populates Subject.NameID from the foreign element, allowing an authenticated principal to spoof Subject.NameID.Value.

Affected packages

ecosystem package affected fixed in
go github.com/crewjam/saml
all versions
 no fix listed

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.