Security Vulnerabilities
fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an error. A host that starts with an opening bracket but does not end with a closing bracket is neither validated as an IP literal nor canonicalized as a domain name, so parse() returns it as the host with error undefined, while Node's URL and the HTTP clients built on it resolve the same string to a different host. An application that reads the parsed host to make a host decision, such as an SSRF denylist, a redirect allowlist, or proxy routing, and then passes the original URL to an HTTP client evaluates its policy against a string that is not the host the request reaches. The same host is carried through normalize, equal, and resolve. This affects fast-uri versions 2.4.5, 3.1.6, and 4.1.3, and is fixed in 2.4.6, 3.1.7, and 4.1.4, where parse() reports a malformed host for any host that contains a bracket but is not a valid IPv6 literal.
CVSS Score
7.5
EPSS Score
0.002
Published
2026-09-03
fast-uri serializes the port component of a URI without validating it. When recomposing the authority, the userinfo and host components are escaped but the port is concatenated verbatim, so a port value that is not a sequence of digits can inject authority delimiters, demoting the intended host to userinfo and pointing the authority at an attacker-controlled host. Both fast-uri and Node's URL read the result back as the attacker's host with no error, so re-validating the built URI does not catch it. This affects applications that build URIs from parts and assign untrusted data to the port component through the serialize, normalize, or equal functions in their object forms. The issue affects fast-uri versions before 2.4.6, from 3.0.0 before 3.1.7, and from 4.0.0 before 4.1.4. It is fixed in 2.4.6, 3.1.7, and 4.1.4, where recomposeAuthority rejects any port that is not a digit sequence per RFC 3986.
CVSS Score
7.5
EPSS Score
0.002
Published
2026-09-02
Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.
CVSS Score
7.5
EPSS Score
0.003
Published
2026-09-02
Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, objects of types marked as storing their configuration in independent top-level configuration files in Jenkins (such as the global configuration and jobs) can appear as nested field values in user-submitted `config.xml` documents and subsequently handle HTTP requests via Stapler, resulting in remote code execution.
CVSS Score
8.8
EPSS Score
0.007
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, user objects can appear as nested field values in other deserialized XML objects, allowing attackers with Overall/Read permission to create user objects by submitting crafted XML.
CVSS Score
4.3
EPSS Score
0.003
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, the system log viewer does not escape log record metadata (source, level, and timestamp) resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers in control of agent processes.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, transient fields cannot be excluded from deserialization, allowing attackers able to submit configuration updates to specify the values of transient fields that will be deserialized, the impact depending on how those fields are used.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, the REST API and CLI endpoints for updating agent configuration do not prevent a submitted configuration from overwriting a different agent by specifying that agent's name in the submitted XML document, allowing attackers with Agent/Configure permission on one agent to take over a different agent, gaining control of its configuration and obtaining access to its inbound agent secret and environment variables.
CVSS Score
6.3
EPSS Score
0.002
Published
2026-09-02
In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the "remember me" cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim's browser, which after the victim authenticates via the "remember me" cookie, grants the attacker access to Jenkins as that user.
CVSS Score
7.3
EPSS Score
0.004
Published
2026-09-02