CVE-2026-129349Apache Shiro improper authentication
CVE-2026-129349 is a improper authentication in Apache Shiro, rated critical (9.1 on CVSS 4.0).
Why this priority: Critical, and reachable over the network without an account.
Published · Updated · NVD status: Received
What it is
The software does not prove who a caller is, so an attacker can pass as someone else.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can read the data it protects and change data or behaviour. In practice, this kind of flaw lets an attacker act as a signed-in user, or an administrator, without valid credentials.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Apache Shiro to 3.0.1 or later.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
When authentication caching is enabled on DefaultLdapRealm, after a user logs in successfully once, subsequent logins for that user succeed with any password. A cached authentication skips the LDAP bind, and the AllowAllCredentialsMatcher installed by default in DefaultLdapRealm accepts any credentials, allowing an attacker who knows a valid username to authenticate as that user. This issue affects all Apache Shiro versions through 3.0.0, only when using DefaultLdapRealm (or JndiLdapRealm) with authenticationCachingEnabled set to true, which is not the default.
Mitigation: Upgrade to version 3.0.1 or later, which fixes the issue by no longer installing AllowAllCredentialsMatcher by default. Alternatively, disable authentication caching on the LDAP realm (this is the default), or configure a credentials matcher, such as SimpleCredentialsMatcher, that verifies credentials against the cached authentication info.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Sign-in, session and token handling. The flaw sits between anonymous callers and authenticated sessions.
- Identity providers and SSO. The flaw sits between anonymous callers and authenticated sessions.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Between anonymous callers and authenticated sessions. An attacker who crosses it can act as a signed-in user, or an administrator, without valid credentials.
Questions to answer about your own systems
- Where does Apache Shiro run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.