Jenkins FilePath.untarFrom() in all versions, including those with the CVE-2026-33001 patch applied, validates symlink destinations but not targets. The CVE-2026-33001 fix enforces that the symlink file is created within the workspace boundary, but the symlink target — the path returned by te.getLinkName() and passed directly to symlinkTo() — is never validated and may point to any path on the controller filesystem. An attacker with Item/Configure permission can configure a job to extract a malicious .tar or .tar.gz archive via a tool installer or custom build step. When FilePath.untarFrom() processes the archive, it creates symlinks inside the workspace that resolve to arbitrary controller paths. By targeting the entire $JENKINS_HOME/secrets/ directory — including master.key, hudson.util.Secret, hudson.model.Secrets.xml, and any other files present — an attacker can exfiltrate all Jenkins cryptographic material through the workspace viewer (GET /job/{name}/ws/) or build artifacts. Combined with credentials.xml and per-user config.xml files, this enables offline AES-128 decryption of all {AQA...}-format credential entries, exposing in plaintext every password, API key, cloud provider secret, and SSH private key stored in the Jenkins credential store — compromising all downstream systems those credentials protect.

In Remoting 3384.v60d89463d9e0 and earlier, except 3355.3357.v931d3c992987, included in Jenkins 2.575 and earlier, LTS 2.568.1 and earlier, the JEP-200 class filter is not applied to classes resolved via a fallback path in the Remoting deserialization implementation, allowing agent processes, code running on agents, and attackers with Agent/Connect permission to bypass the JEP-200 deserialization filter for classes on the Jenkins core classpath.

Jenkins 2.575 and earlier, LTS 2.568.1 and earlier does not safely handle symbolic links with effectively empty names during the extraction of `.tar` and `.tar.gz` archives, allowing attackers able to control agent processes to provide crafted archives to the controller to write files to arbitrary locations on the file system, restricted only by file system access permissions of the user running Jenkins.

Jenkins 2.575 and earlier, LTS 2.568.1 and earlier improperly identifies file paths attempting path traversal in file parameter names, allowing attackers with Item/Configure and Item/Build permission to write files to arbitrary locations on the controller file system.

Jenkins 2.575 and earlier, LTS 2.568.1 and earlier does not restrict the types of objects that can be instantiated as part of the project naming strategy configuration, allowing attackers with Overall/Manage permission to instantiate arbitrary types related to configuration, including those intended for configuration only by administrators.

Jenkins 2.575 and earlier, LTS 2.568.1 and earlier handles case-insensitivity in user names and group names inconsistently, allowing attackers able to create new users or groups with names that case-insensitively match other characters to impersonate other users or be granted their permissions in some circumstances.

Jenkins 2.554 and earlier, LTS 2.541.2 and earlier does not safely handle symbolic links during the extraction of .tar and .tar.gz archives, allowing crafted archives to write files to arbitrary locations on the filesystem, restricted only by file system access permissions of the user running Jenkins. This can be exploited to deploy malicious scripts or plugins on the controller by attackers with Item/Configure permission, or able to control agent processes.

Jenkins 2.442 through 2.554 (both inclusive), LTS 2.426.3 through LTS 2.541.2 (both inclusive) performs origin validation of requests made through the CLI WebSocket endpoint by computing the expected origin for comparison using the Host or X-Forwarded-Host HTTP request headers, making it vulnerable to DNS rebinding attacks that allow bypassing origin validation.