Jenkins Credentials Plugin Arbitrary File Write Vulnerability

Jenkins Credentials Binding Plugin 719.v80e905ef14eb_ and earlier does not sanitize file names for file and zip file credentials, allowing attackers able to provide credentials to a job to write files to arbitrary locations on the node filesystem, which can lead to remote code execution if Jenkins is configured to allow a low-privileged user to configure file or zip file credentials used for a job running on the built-in node.

Casky was already ahead

This CVE exploits attack patterns that Casky's 331matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

Jenkins Credentials Binding Plugin versions 719.v80e905ef14eb_ and earlier contain a path traversal vulnerability (CWE-22) that fails to sanitize file names in file and zip file credentials. Attackers with the ability to provide credentials to a Jenkins job can exploit this flaw to write files to arbitrary locations on the node filesystem. This is particularly critical in environments where Jenkins permits low-privileged users to configure credentials, as successful exploitation can lead to remote code execution by placing malicious files in executable paths or configuration directories. Organizations running vulnerable Jenkins instances with permissive credential configuration policies face significant risk of compromise.

Casky.ai's 331 mapped security skills leverage Claude's extended reasoning to detect the attack patterns underlying this vulnerability across MITRE ATT&CK's Initial Access (TA0001) and Discovery (TA0007) techniques. Practitioners using Casky would identify suspicious indicators including: unusual file write operations to system directories during Jenkins job execution, credential objects containing path traversal sequences (../ patterns) in file name fields, and anomalous file creation outside expected Jenkins workspace directories. The platform's skill mapping would correlate these behavioral signals with post-exploitation activities such as privilege escalation attempts or lateral movement following initial file writes, enabling security teams to detect both the exploitation attempt and downstream attacker actions in their Jenkins infrastructure.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

331 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-42520.

analyzing-cloud-storage-access-patterns

cloud security · low

Run

analyzing-ios-app-security-with-objection

mobile security · low

Run

analyzing-malicious-url-with-urlscan

phishing defense · medium

Run

MITRE ATT&CK Techniques

TA0001 TA0007

Investigate the attack patterns behind CVE-2026-42520

Casky has 331 skills that investigate the attack patterns behind CVE-2026-42520. Run one and get CVSS-scored findings in 3 minutes.

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