GHSA-hwqm-qvj9-4jr2: github.com/russellhaering/gosaml2

gosaml2 CBC Padding Panic — Unauthenticated Process Crash

CVSS 4.0, no score published

Published by the GitHub Advisory Database at 18 Mar 2026, 20:19 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
github.com/russellhaering/gosaml2	Go	<0.11.0	0.11.0

Identifiers

GHSA-hwqm-qvj9-4jr2 · GO-2026-4760

Weakness (CWE)

CWE-129

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Versions of gosaml2 before 0.11.0 panic when decrypting an AES-CBC encrypted assertion whose decrypted plaintext is all zero bytes. An unauthenticated attacker who knows the service provider's public RSA key, which is published in SAML metadata, can send one crafted HTTP POST to the assertion consumer endpoint, crashing the process or the request goroutine, and can repeat it. Upgrade to gosaml2 0.11.0 or later.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
Not published	None	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	GitHub Advisory Database

CISA KEV Not listed.
EPSS No score.

Timeline

31 Oct 2026, 14:14 UTC First seen by agentprime
31 Oct 2026, 14:14 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.