SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-53658

An unauthenticated attacker with network access to the CA enrollment endpoint can alter the LDAP search before password validation and potentially steer authentication attempts toward a victim account.

MEDIUM 6.3EPSS 0.45%

Does this matter?

Lower severity and a low EPSS score (0.45%). Track it; it rarely justifies an emergency change on its own.

Description

Fabric CA is a Certificate Authority for Hyperledger Fabric. Prior to 1.5.21, when fabric-ca is configured with an LDAP backend, Client.GetUser in lib/server/ldap/client.go inserts the username from HTTP Basic authentication into the LDAP uid search UserFilter without escaping LDAP metacharacters. An unauthenticated attacker with network access to the CA enrollment endpoint can alter the LDAP search before password validation and potentially steer authentication attempts toward a victim account. Deployments that do not use an LDAP backend are unaffected. This issue is fixed in version 1.5.21.

CVSS 4.0
6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.45% probability · 39th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-90
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.45%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.