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Threats / Jenkins / CVE-2018-1000861
CVE-2018-1000861 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-06

Jenkins Stapler Web Framework vulnerability

A deserialization vulnerability in Jenkins Stapler Web Framework allows remote code execution. The flaw has been exploited in the wild.

Verdict

Today item — known-exploited.

CVE-2018-1000861 is a critical remote code execution vulnerability in the Stapler framework used by Jenkins. Unsafe deserialization of untrusted data enables unauthenticated attackers to execute arbitrary code, with confirmed active exploitation.

CISA KEV Yes · 2022-02-103EPSS 0.94485 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-02-10).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.94485 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
FIRST EPSS ↗High
Severity / affected
Affected: Jenkins, Jenkins Stapler Web Framework. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-502 Deserialization of Untrusted Data — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-502 · Deserialization of Untrusted DataInjection
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No threat-actor attribution is established from the public feed for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
I craft a malicious serialized Java object and send it to a vulnerable Jenkins instance via the Stapler framework.
Business
Attackers gain immediate code execution on Jenkins servers, compromising CI/CD pipelines and build infrastructure.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I execute commands with the privileges of the Jenkins process to establish persistence and lateral movement.
Business
Threat actors pivot to connected systems, steal credentials, and compromise source code repositories and deployment targets.
3

Lateral reach — past segmentation narrative 3

Attacker
I exfiltrate sensitive data including build artifacts, credentials, and configuration from the compromised Jenkins instance.
Business
Intellectual property, API keys, and deployment secrets are exposed, enabling further attacks on downstream systems and customers.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • CWE weakness mapping (NVD)
  • Catalogued by mitre (CNA)

    • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
    • Disclosure & credit2
    Catalogued by mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.