CVE-2026-41081
Apache Storm Client: Anonymous principal assigned on TLS client certificate verification failure
Description
Improper Handling of TLS Client Authentication Failure Leading to Anonymous Principal Assignment in Apache Storm Versions Affected: up to 2.8.7 Description: When TLS transport is enabled in Apache Storm without requiring client certificate authentication (the default configuration), the TlsTransportPlugin assigns a fallback principal (CN=ANONYMOUS) if no client certificate is presented or if certificate verification fails. The underlying SSLPeerUnverifiedException is caught and suppressed rather than rejecting the connection. This fail-open behavior means an unauthenticated client can establish a TLS connection and receive a valid principal identity. If the configured authorizer (e.g., SimpleACLAuthorizer) does not explicitly deny access to CN=ANONYMOUS, this may result in unauthorized access to Storm services. The condition is logged at debug level only, reducing visibility in production. Impact: Unauthenticated clients may be assigned a principal identity, potentially bypassing authorization in permissive or misconfigured environments. Mitigation: Users should upgrade to 2.8.7 in which TLS authentication failures are handled in a fail-closed manner. Users who cannot upgrade immediately should: - Enable mandatory client certificate authentication (nimbus.thrift.tls.client.auth.required: true) - Ensure authorization rules explicitly deny access to CN=ANONYMOUS - Review all ACL configurations for implicit default-allow behavior
INFO
Published Date :
April 27, 2026, 2:16 p.m.
Last Modified :
April 28, 2026, 7:46 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Upgrade Apache Storm to version 2.8.7.
- Enable mandatory client certificate authentication.
- Deny access to CN=ANONYMOUS in authorization rules.
- Review all ACL configurations for default-allow behavior.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-41081.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/plxx5l29dvplk5rwzdcq53rdfl6v4gs8 | Mailing List Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2026/04/25/3 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-41081 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-41081
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-41081 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-41081 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 28, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:apache:storm:*:*:*:*:*:*:*:* versions up to (excluding) 2.8.7 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/04/25/3 Types: Mailing List, Third Party Advisory Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/plxx5l29dvplk5rwzdcq53rdfl6v4gs8 Types: Mailing List, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Apr. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N -
New CVE Received by [email protected]
Apr. 27, 2026
Action Type Old Value New Value Added Description Improper Handling of TLS Client Authentication Failure Leading to Anonymous Principal Assignment in Apache Storm Versions Affected: up to 2.8.7 Description: When TLS transport is enabled in Apache Storm without requiring client certificate authentication (the default configuration), the TlsTransportPlugin assigns a fallback principal (CN=ANONYMOUS) if no client certificate is presented or if certificate verification fails. The underlying SSLPeerUnverifiedException is caught and suppressed rather than rejecting the connection. This fail-open behavior means an unauthenticated client can establish a TLS connection and receive a valid principal identity. If the configured authorizer (e.g., SimpleACLAuthorizer) does not explicitly deny access to CN=ANONYMOUS, this may result in unauthorized access to Storm services. The condition is logged at debug level only, reducing visibility in production. Impact: Unauthenticated clients may be assigned a principal identity, potentially bypassing authorization in permissive or misconfigured environments. Mitigation: Users should upgrade to 2.8.7 in which TLS authentication failures are handled in a fail-closed manner. Users who cannot upgrade immediately should: - Enable mandatory client certificate authentication (nimbus.thrift.tls.client.auth.required: true) - Ensure authorization rules explicitly deny access to CN=ANONYMOUS - Review all ACL configurations for implicit default-allow behavior Added CWE CWE-287 Added Reference https://lists.apache.org/thread/plxx5l29dvplk5rwzdcq53rdfl6v4gs8 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Apr. 27, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/04/25/3