Summary
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.
Impact
CVE-2026-48920 has a CVSS score of 8.8 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1933.1935.v276319e3cc47); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-48920? CVE-2026-48920 is a high-severity security vulnerability in org.jenkins-ci.plugins:email-ext (maven), affecting versions < 1933.1935.v276319e3cc47. It is fixed in 1933.1935.v276319e3cc47.
- How severe is CVE-2026-48920? CVE-2026-48920 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.jenkins-ci.plugins:email-ext are affected by CVE-2026-48920? org.jenkins-ci.plugins:email-ext (maven) versions < 1933.1935.v276319e3cc47 is affected.
- Is there a fix for CVE-2026-48920? Yes. CVE-2026-48920 is fixed in 1933.1935.v276319e3cc47. Upgrade to this version or later.
- Is CVE-2026-48920 exploitable, and should I be worried? Whether CVE-2026-48920 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-48920 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-48920? Upgrade
org.jenkins-ci.plugins:email-extto 1933.1935.v276319e3cc47 or later.