VulnerabilityPublished 18 Feb 2026

CVE-2026-27100: Jenkins · Information Exposure

Affects JenkinsSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Jenkins ProjectJenkins	Affected–	Fixed in–

AI-suggested

To mitigate CVE-2026-27100, European organizations should implement the following specific measures: 1) Conduct a thorough audit of Jenkins user permissions, ensuring that only trusted users have Item/Build and Item/Configure permissions, and apply the principle of least privilege rigorously. 2) Restrict the ability to submit Run Parameter values to users who absolutely require it, and consider disabling or limiting parameterized builds where feasible. 3) Monitor Jenkins logs for unusual parameter submissions or attempts to reference unauthorized builds, enabling early detection of exploitation attempts. 4) Implement network segmentation and access controls to limit Jenkins access to trusted internal users and systems. 5) Stay informed on Jenkins security advisories and apply patches or updates promptly once available for this vulnerability. 6) Consider deploying additional security controls such as Web Application Firewalls (WAFs) or runtime application self-protection (RASP) solutions that can detect and block suspicious parameter manipulation. 7) Educate Jenkins administrators and developers about secure configuration practices and the risks of excessive permissions. These targeted actions go beyond generic advice by focusing on permission hygiene, monitoring, and proactive defense tailored to this vulnerability’s characteristics.

Description

Jenkins 2.550 and earlier, LTS 2.541.1 and earlier accepts Run Parameter values that refer to builds the user submitting the build does not have access to, allowing attackers with Item/Build and Item/Configure permission to obtain information about the existence of jobs, the existence of builds, and if a specified build exists, its display name.

Impact

For European organizations, the impact of CVE-2026-27100 centers on information disclosure within Jenkins environments. While the vulnerability does not allow direct compromise of build artifacts or code integrity, leaking job and build existence and display names can facilitate targeted attacks, such as spear phishing or privilege escalation attempts. Organizations with complex Jenkins setups and multiple teams may inadvertently expose sensitive project metadata to users who should not have that visibility. This can undermine confidentiality and increase the risk of insider threats or lateral movement within the network. The impact is more pronounced in environments where permissions are broadly assigned or not regularly audited. Since Jenkins is integral to software development and deployment, any compromise or reconnaissance advantage can disrupt development workflows and delay releases. European companies in sectors like finance, manufacturing, and technology that rely heavily on Jenkins for CI/CD pipelines could face operational risks if attackers use this information to plan further attacks. However, the requirement for authenticated users with specific permissions limits the scope to internal or trusted users, reducing the likelihood of external attackers exploiting this vulnerability directly. Overall, the impact is moderate but should not be underestimated in sensitive or high-value environments.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

jenkins.io/security/advisory/2026-02-18/ (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Feb 2026, 14:58 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

Related threats