Improper Input Validation in Jakarta Expression Language

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2021-28170: 2.13% estimated exploitation activity in the next 30 days; percentile 82.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

In the Jakarta Expression Language implementation 3.0.3 and earlier, a bug in the ELParserTokenManager enables invalid EL expressions to be evaluated as if they were valid.

Published by the source

6 Oct 2021, 17:48 UTC

Last modified by the source

1 Jul 2025, 16:13 UTC

Source last checked

26 Oct 2026, 16:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v6w3-2prq-h95f

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# Patch Next advisory brief: CVE-2021-28170

Advisory: Improper Input Validation in Jakarta Expression Language
IDs: CVE-2021-28170, GHSA-v6w3-2prq-h95f
Record: https://patchnext.com/advisories/cve-2021-28170 (revision 1, source checked 26 Oct 2026, 16:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: com.sun.el:el-ri 3.0.4; org.glassfish:jakarta.el 3.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven com.sun.el:el-ri: affected < 3.0.4; fixed in 3.0.4
- Maven org.glassfish:jakarta.el: affected < 3.0.4; fixed in 3.0.4
- Maven org.glassfish:javax.el: affected <= 3.0.1-b12

## Suggested inspection (read-only)
- Maven com.sun.el:el-ri: check the installed version with your package manager.
- Maven org.glassfish:jakarta.el: check the installed version with your package manager.
- Maven org.glassfish:javax.el: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on com.sun.el:el-ri, org.glassfish:jakarta.el, org.glassfish:javax.el.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v6w3-2prq-h95f (GitHub-reviewed advisory GHSA-v6w3-2prq-h95f lists affected ranges: Maven com.sun.el:el-ri >=0 =0 =0 <=3.0.1-b12)

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