GHSA-26wc-3wqp-g3rp CVE-2017-1000353
Deserialization of Untrusted Data in Jenkins
- Severity
- 9.8 / 10
- Critical · CVSS 3.0
- Exploit chance (EPSS)
- 99.68%
- Chance of exploitation in the next 30 days. Higher than 99.95% of scored vulnerabilities.
- Known exploited
- Yes
- In CISA's catalog since Oct 2, 2025
- Weakness
- CWE-502 Deserialization of Untrusted Data
- Fix
2.57- Upgrade org.jenkins-ci.main:jenkins-core to this version or later
Description
Jenkins versions 2.56 and earlier as well as 2.46.1 LTS and earlier are vulnerable to an unauthenticated remote code execution. An unauthenticated remote code execution vulnerability allowed attackers to transfer a serialized Java SignedObject object to the Jenkins CLI, that would be deserialized using a new ObjectInputStream, bypassing the existing blacklist-based protection mechanism. We're fixing this issue by adding SignedObject to the blacklist. We're also backporting the new HTTP CLI protocol from Jenkins 2.54 to LTS 2.46.2, and deprecating the remoting-based (i.e. Java serialization) CLI protocol, disabling it by default.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| org.jenkins-ci.main:jenkins-core | >= 2.50, <= 2.56 |
No fix yet |
| org.jenkins-ci.main:jenkins-core | <= 2.46.1 |
No fix yet |
| org.jenkins-ci.main:jenkins-core | >= 2.50, < 2.57 |
2.57 |
| org.jenkins-ci.main:jenkins-core | < 2.46.2 |
2.46.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
org.jenkins-ci.main:jenkins-core Maven → 2.57
- maven
<dependency><groupId>org.jenkins-ci.main</groupId><artifactId>jenkins-core</artifactId><version>2.57</version></dependency>- gradle
implementation("org.jenkins-ci.main:jenkins-core:2.57")
Severity breakdown
CVSS 3.0 9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
- Exploit maturity
- H
Weakness
CWE-502: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How to prevent it
- Architecture and Design, Implementation: If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- Implementation: When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Implementation: Explicitly define a final object() to prevent deserialization.
- Architecture and Design, Implementation: Make fields transient to protect them from deserialization. An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
- Implementation: Avoid having unnecessary types or gadgets (a sequence of instances and method invocations that can self-execute during the deserialization process, often found in libraries) available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.
- Architecture and Design, Implementation: Employ cryptography of the data or code for protection. However, it's important to note that it would still be client-side security. This is risky because if the client is compromised then the security implemented on the client (the cryptography) can be bypassed.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Advisories
Fixes and patches
Packages
Other links
Timeline
- Published
- Added to CISA's Known Exploited Vulnerabilities catalog
- Last updated by the source
- Remediation due for U.S. federal agencies
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-6f9g-cxwr-q5jr Arbitrary file read vulnerability through the Jenkins CLI can lead to RCE | Critical Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-8pqx-3rxx-f5pm Jenkins discloses project names via fingerprints | High Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| CVE-2018-1000861 Deserialization of Untrusted Data in Jenkins | Critical Known exploited | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-m6wv-wh8g-64xc Jenkins does not encrypt secrets from POST config.xml submissions before storing them in job configurations | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-93qh-vwrm-c5pw Jenkins: Stored XSS vulnerability in node offline cause description | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-92m7-4fpw-2wxm Jenkins: Open Redirect phishing attacks possible via "from" parameter in "Delegate to servlet container" | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-g28p-6mcc-v4rv Jenkins exposes other users' timezone and view names to users with Overall/Read permission | Medium | Also affects org.jenkins-ci.main:jenkins-core |
| GHSA-mw82-xcg6-gx79 Jenkins: Missing permission check allows unauthorized cancellation of queue items | Medium | Also affects org.jenkins-ci.main:jenkins-core |
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