LDAPCache and LDAPBackingEngine build LDAP search filters for user lookup and role lookup by textually substituting the placeholders %u, %dn, and %fqdn (drawn from the login name, the resolved user DN, and its fully qualified namespace form) into administrator-configured filter templates (userFilter, roleFilter). Before the fix, the only sanitization applied to the substituted value was double backslashed:
filter = filter.replaceAll(Pattern.quote("%u"), Matcher.quoteReplacement(user));
filter = filter.replace("\\", "\\\\");
This does not escape the other characters RFC 4515 requires escaping in an LDAP search filter: *, (, ), and NUL. A login name containing any of these can change the structure of the resulting filter rather than being matched as a literal value (e.g. a crafted username can turn an equality match into a wildcard match, or close/reopen filter clauses), widening what the search returns and potentially causing a login or role lookup to match an LDAP entry other than the intended one, over-granting roles, and depending on deployment-specific filter templates, potentially affecting which account a login resolved to.
It's not exploitable through every entry points: LDAPLoginModule and LDAPPubkeyLoginModule both called Util.doRFC2254Encoding() (correct RFC 4515 escaping) on the login name before handing it to LDAPCache, which masked the missing escaping in LDAPCache for those two call paths. Using LDAPCache directly (bypassing the login modules) does not reproduce through the normal LDAPLoginModule/LDAPPubkeyLoginModule authentication flow for this reason. It does reproduce through two other call paths that reach LDAPCache/LDAPBackingEngine without any prior escaping:
* GSSAPILdapLoginModule passes the NameCallback name straight through, unescaped.
* LDAPBackingEngine (listRoles) passes principal.getName() straight through, unescaped.
References
| Link | Resource |
|---|---|
| https://karaf.apache.org/security/cve-2026-90979.txt | Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/09/28/2 | Mailing List Third Party Advisory |
Configurations
History
08 Oct 2026, 19:20
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Apache
Apache karaf |
|
| References | () https://karaf.apache.org/security/cve-2026-90979.txt - Vendor Advisory | |
| References | () http://www.openwall.com/lists/oss-security/2026/09/28/2 - Mailing List, Third Party Advisory | |
| CPE | cpe:2.3:a:apache:karaf:*:*:*:*:*:*:*:* |
30 Sep 2026, 20:17
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.3 |
28 Sep 2026, 14:17
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
28 Sep 2026, 10:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-28 10:16
Updated : 2026-10-08 19:20
NVD link : CVE-2026-90979
Mitre link : CVE-2026-90979
CVE.ORG link : CVE-2026-90979
JSON object : View
Products Affected
apache
- karaf
CWE
CWE-90
Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')