SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-77998

Joomla Extension - miniorange.com - Unauthenticated Authentication Bypass via SAMLResponse Parameter in miniOrange SAML SSO < 11.0.2, SAML SP Single Sign On – Login with ADFS < 6.4, SAML SP Single Sign On – SAML SSO login with Google Apps < 6.4 - This…

CRITICAL 10.0EPSS 0.34%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Joomla Extension - miniorange.com - Unauthenticated Authentication Bypass via SAMLResponse Parameter in miniOrange SAML SSO < 11.0.2, SAML SP Single Sign On – Login with ADFS < 6.4, SAML SP Single Sign On – SAML SSO login with Google Apps < 6.4 - This is due to the mo_saml_validate_signature() function performing a loose boolean check on the raw tri-state integer returned by PHP's openssl_verify(), causing an error return value of -1 to be evaluated as truthy and therefore treated as a successful signature verification. This makes it possible for unauthenticated attackers to log in as any existing Joomla user, including administrators, by submitting a crafted SAMLResponse containing an attacker-controlled NameID and a deliberately malformed signature value that triggers an OpenSSL processing error — bypassing verification entirely and resulting in wp_set_auth_cookie() being called for the targeted account.

CVSS 4.0
10.0 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.34% probability · 27th percentile
CISA KEV
Not listed
Weakness
CWE-639
Source
security@joomla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.