How severe is CVE-2026-27099?

CVE-2026-27099 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-27099 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27099?

CVE-2026-27099 primarily affects Jenkins. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-27099?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-27099 have an EU (EUVD) identifier?

Yes. CVE-2026-27099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8091.

When was CVE-2026-27099 published?

CVE-2026-27099 was published on 2026-02-18 and last updated on 2026-06-17.

CVE-2026-27099

CVE-2026-27099 is a high-severity vulnerability in Jenkins with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 8.0)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8091
Weakness: CWE-79
Affected product: Jenkins
Published: 2026-02-18
Last modified: 2026-06-17

Description

Jenkins 2.483 through 2.550 (both inclusive), LTS 2.492.1 through 2.541.1 (both inclusive) does not escape the user-provided description of the "Mark temporarily offline" offline cause, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure or Agent/Disconnect permission.

Frequently asked questions

What is CVE-2026-27099?: Jenkins 2.483 through 2.550 (both inclusive), LTS 2.492.1 through 2.541.1 (both inclusive) does not escape the user-provided description of the "Mark temporarily offline" offline cause, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure or Agent/Disconnect permission.
How severe is CVE-2026-27099?: CVE-2026-27099 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-27099 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27099?: CVE-2026-27099 primarily affects Jenkins. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-27099?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-27099 have an EU (EUVD) identifier?: Yes. CVE-2026-27099 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8091.
When was CVE-2026-27099 published?: CVE-2026-27099 was published on 2026-02-18 and last updated on 2026-06-17.

References

https://www.jenkins.io/security/advisory/2026-02-18/#SECURITY-3669

Affected products (2)

cpe:2.3:a:jenkins:jenkins:*:*:*:*:-:*:*:*
cpe:2.3:a:jenkins:jenkins:*:*:*:*:lts:*:*:*

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CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
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Threat intelligence

Threat-intel indicators referencing this CVE:

125.212.235.194 (ipv4-addr)
220.95.208.142 (ipv4-addr)
209.182.232.150 (ipv4-addr)
4.213.224.194 (ipv4-addr)