CVSS 3.1
3.4 lowCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:NCVE-2025-7339
Low (3.4). EPSS 0.2% chance of exploitation in the next 30 days. Fixed in on-headers 1.1.0.
on-headers is a node.js middleware for listening to when a response writes headers. A bug in on-headers versions `<1.1.0` may result in response headers being inadvertently modified when an array is passed to `response.writeHead()`. Users should upgrade to version 1.1.0 to receive a patch. Uses are strongly encouraged to upgrade to `1.1.0`, but this issue can be worked around by passing an object to `response.writeHead()` rather than an array.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 10% of CVEs (scores of 2026-10-31)
- CWE
- CWE-241
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-76c9-3jph-rj3q | npm | on-headers | <1.1.0 | 1.1.0 |
References
- https://cna.openjsf.org/security-advisories.html
- https://github.com/expressjs/morgan/issues/315
- https://github.com/jshttp/on-headers/commit/c6e384908c9c6127d18831d16ab0bd96e1231867
- https://github.com/jshttp/on-headers/issues/15
- https://github.com/jshttp/on-headers/security/advisories/GHSA-76c9-3jph-rj3q