What it is
GHSA-G2XQ-2V27-4RH3 is a vulnerability affecting org.jenkins-ci.main jenkins-core. In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types...
Vulnerability report
Exploited in the wild
High confidence
Not in CISA KEV
GHSA-G2XQ-2V27-4RH3
Linked CVE: CVE-2026-53435
jenkins-core Deserialization
org.jenkins-ci.main / jenkins-core · All versions (default: affected)
- Severity
- CVSS 8.8 · High
- Confidence
- High
- Exploit status
- Exploited in the wild
- EPSS
- 19.0%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is high.
Who is affected?
org.jenkins-ci.main / jenkins-core all versions (default: affected).
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
jenkins-core Deserialization
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.
Vendor
Product
Affected
Status
Jenkins Project
Jenkins
Before *
Unaffected
Jenkins Project
Jenkins
Before 2.555.*
Unaffected
- Published
- 10 Jun 2026
- Exploitation Reported
- 15 Jun 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
CVE References
- https://github.com/advisories/GHSA-g2xq-2v27-4rh3 GitHub Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-53435 Reference
- https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3707 Reference
- https://access.redhat.com/security/cve/CVE-2026-53435 Reference
- https://bugzilla.redhat.com/show_bug.cgi?id=2487539 Reference
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53435.json Reference
- https://github.com/jenkinsci/jenkins/commit/345a3190a49d1ac96c4ff1c2e9eef4102c8d63f6 Reference
- https://github.com/jenkinsci/jenkins/commit/d739f6a6266d Reference
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-53435
Exploitation evidence
Why KEV Intelligence marks this advisory as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
Defused Cyber
Independent exploitation attestation added to the KEV Intelligence record.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence 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
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence 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
Severity, weaknesses, and research context
CVSS v3.1
8.8
High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
19.0%
Weaknesses
Recent mention · Daily CyberSecurity
Jenkins RCE Vulnerability CVE-2026-53435 Now Under Active Exploitation
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
From disclosure to observed exploitation
-
KEV confirmed by Daily CyberSecurity
Exploitation attested by an external source
-
Added to KEV Intelligence KEV Feed
High-confidence, third-party attested exploitation
-
GitHub Advisory published
Vulnerability disclosed publicly
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/GHSA-G2XQ-2V27-4RH3
Free JSON includes basic KEV fields{
"ghsa_id": "GHSA-G2XQ-2V27-4RH3",
"confidence": "High",
"cvss_score": 8.8,
"cvss_estimated": false,
"epss_score": 0.19035,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.