No Charset in Content-Type Header in express

Exploitation

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

CVSS

6.1 · CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2014-6393: 1.14% estimated exploitation activity in the next 30 days; percentile 66.76 (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.

Vulnerable versions of express do not specify a charset field in the content-type header while displaying 400 level response messages. The lack of enforcing user's browser to set correct charset, could be leveraged by an attacker to perform a cross-site scripting attack, using non-standard encodings, like UTF-7. Recommendation For express 3.x, update express to version 3.11 or later. For express 4.x, update express to version 4.5 or later.

Published by the source

23 Oct 2018, 17:22 UTC

Last modified by the source

8 Nov 2023, 03:57 UTC

Source last checked

26 Oct 2026, 12:20 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-gpvr-g6gh-9mc2

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-gpvr-g6gh-9mc2

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# Patch Next advisory brief: CVE-2014-6393

Advisory: No Charset in Content-Type Header in express
IDs: CVE-2014-6393, GHSA-gpvr-g6gh-9mc2
Record: https://patchnext.com/advisories/cve-2014-6393 (revision 2, source checked 26 Oct 2026, 12:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: express 4.5.0, 3.11.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm express: affected < 3.11.0; >= 4.0.0, < 4.5.0; fixed in 4.5.0, 3.11.0

## Suggested inspection (read-only)
- `npm ls express --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on express.
- 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://osv.dev/vulnerability/GHSA-gpvr-g6gh-9mc2 (OSV record GHSA-gpvr-g6gh-9mc2 lists affected ranges: npm express >=0 =4.0.0 <4.5.0 (fixed))
- Verified: https://github.com/advisories/GHSA-gpvr-g6gh-9mc2 (GitHub-reviewed advisory GHSA-gpvr-g6gh-9mc2 lists affected ranges: npm express >=0 =4.0.0 <4.5.0)

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