dbcve.org
JenkinsApplication

CVE-2026-27099

HIGH · 8.0 CVSS v3.1 Published 2026-02-18
Fix available
A fix is available. Upgrade to 2.541.2 / 2.551 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Jenkins fails to escape user-provided description in the 'Mark temporarily offline' feature, allowing stored XSS injection. Attackers with Agent/Configure or Agent/Disconnect permissions can embed malicious scripts in the offline cause description that execute when other users view the agent status.

MitigationUpgrade Jenkins to version 2.551 or LTS 2.542.1 or later to receive the patch, or restrict Agent/Configure and Agent/Disconnect permissions to trusted users only until patching is feasible.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JenkinsApplication
Affected:>= 2.483, < 2.551>= 2.492.1, < 2.541.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Jenkins version
    Navigate to Manage Jenkins > About Jenkins or access /whoAmI/ API endpoint to retrieve the exact version number
    Affected if The installed version is 2.483 <= version < 2.551 OR 2.492.1 <= version < 2.541.2 (or if version cannot be determined but Jenkins is known to be from this period)
  2. Review Agent/Configure permissions
    Navigate to Manage Jenkins > Manage Users and check User IDs with Overall/Administer or Agent/Configure permissions. Also check if any Matrix Authorization Strategy grants Agent/Configure to untrusted users
    Affected if Users other than trusted administrators have Agent/Configure permission granted directly or via group/role matrix
  3. Review Agent/Disconnect permissions
    Navigate to Manage Jenkins > Manage Users and check which users have Agent/Disconnect permission. Review any configured Matrix Authorization Strategy or Project-based Matrix Authorization Strategy
    Affected if Users other than trusted administrators have Agent/Disconnect permission granted
  4. Inspect agent offline descriptions
    Navigate to Manage Jenkins > Manage Nodes. For each agent, click the agent name and review the Status section. Check if any offline cause description field contains non-standard characters, scripts, or unexpected HTML tags
    Affected if Any agent shows a custom offline cause description containing script tags, javascript: URLs, or other potentially malicious HTML/JavaScript content
  5. Check for recent offline/online agent events
    Review Jenkins logs (Manage Jenkins > System Log) or agent status history for entries indicating agents were marked offline and back online, noting who performed the action
    Affected if Agent offline events show unknown or untrusted users performing Mark Temporary Offline actions with custom descriptions

Environment is affected if Jenkins version falls within the vulnerable ranges AND untrusted users have Agent/Configure or Agent/Disconnect permissions, or if any agent already displays a suspicious offline cause description containing script or HTML tags.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.541.2 / 2.551 or later
Fixed in 2.541.22.551
Interim mitigation

Upgrade Jenkins to version 2.551 or LTS 2.542.1 or later to receive the patch, or restrict Agent/Configure and Agent/Disconnect permissions to trusted users only until patching is feasible.

Recommended fix High confidence

Jenkins 2.551 (weekly) or Jenkins 2.541.2 LTS

  1. 1. Identify the current Jenkins version by navigating to Manage Jenkins > About Jenkins
  2. 2. If running a weekly release >= 2.483 and < 2.551, upgrade to Jenkins 2.551 or later
  3. 3. If running an LTS release >= 2.492.1 and < 2.541.2, upgrade to Jenkins 2.541.2 LTS or later
  4. 4. After upgrade, verify the 'Mark temporarily offline' feature now properly escapes HTML in the offline cause description
  5. 5. Test that users with Agent/Configure or Agent/Disconnect permissions cannot inject XSS payloads through the offline cause description field

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Jenkins Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-27099 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27099 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data