What it is
CVE-2026-53435 is a vulnerability affecting Jenkins Project Jenkins. In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins...
Vulnerability report
Jenkins
Jenkins Project / Jenkins · affected before *
Decision summary
Direct answers before the deeper technical record.
What it is
CVE-2026-53435 is a vulnerability affecting Jenkins Project Jenkins. In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins...
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.
Who is affected?
Jenkins Project / Jenkins affected before *.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins core or plugins from an attacker-controlled `config.xml` submission in a way that allows them to handle HTTP requests afterwards.
This can be used to impersonate any user and send HTTP requests on their behalf, up to and including use of the Script Console to run arbitrary code, or to read arbitrary files from the Jenkins controller.
Exploitation evidence
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Defused Cyber
A trusted third party reported exploitation.
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| Defused Cyber First | 2026-06-15 09:02 UTC |
| Daily CyberSecurity | 2026-06-15 10:20 UTC |
Detection
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
No scanner integrations recorded yet.
No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
CVSS v3.1
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
2.2%
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
Recent mention · Daily CyberSecurity
Attackers are already abusing a critical Jenkins RCE vulnerability in the wild. Tracked as CVE-2026-53435, the flaw lets The post Jenkins RCE Vulnerability CVE-2026-53435 Now Under Active Exploitation appeared first on Daily CyberSecurity. Related posts: High-Severity RCE...
Read full advisoryTimeline
10:20 UTC
Exploitation attested by an external source
09:02 UTC
High-confidence, third-party attested exploitation
13:05 UTC
Vulnerability disclosed publicly
14:26 UTC
Identifier reserved by the CNA
Pro API
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
GET /api/v2/pro/kevs/CVE-2026-53435
Free JSON includes basic KEV fields{
"cve_id": "CVE-2026-53435",
"confidence": "High",
"cvss_score": 8.8,
"cvss_estimated": false,
"epss_score": 0.02163,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}