High

Jenkins Email Extension Plugin: Attackers able to control email content may specify `file:` URLs for images to read arbitrary files from Jenkins controller filesystem

  • Disclosed: 27.05.2026
  • Updated: 11.10.2026 12:22

Jenkins Email Extension Plugin 1933.v45cec755423f and earlier includes a feature that allows inlining images as base64 in email content by setting the data-inline attribute. No restrictions are placed on the image URLs that can be inlined.

This allows attackers able to control the email content to specify file: URLs for images to read arbitrary files from the Jenkins controller filesystem.

The feature allowing inlining images as base64 in email content by setting the data-inline attribute is removed from Email Extension Plugin 1933.1935.v276319e3cc47.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.jenkins-ci.plugins:email-ext < 1933.1935.v276319e3cc47 1933.1935.v276319e3cc47

References

CVSS score 8.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-73
Platform
Java / Kotlin (Maven)
Package
org.jenkins-ci.plugins:email-ext
Disclosed
27.05.2026
Updated
11.10.2026 12:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-mq58-m26g-46gp - CC BY 4.0

Vulnerability history: org.jenkins-ci.plugins:email-ext

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (12) in the archive
Total entries
12
First → latest
05.2022 05.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 2
  • High 2
  • Medium 7
  • Low 1

Disclosures per year

  1. 2022: 6
  2. 2023: 5
  3. 2024: 0
  4. 2025: 0
  5. 2026: 1
Severity:
  1. Jenkins Email Extension Plugin: Attackers able to control email content may specify `file:` URLs for images to read arbitrary files from Jenkins controller filesystem this entry
    High · 8.8 CVE-2026-48920 < 1933.1935.v276319e3cc47 1933.1935.v276319e3cc47
  2. Critical · 9.9 CVE-2023-25765 < 2.94 2.94
  3. High · 8.1 CVE-2018-1000417 < 1.1 1.1
  4. Critical · 9.9 CVE-2019-1003032 < 2.65 2.65

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