Machine-In-The-Middle in https-proxy-agent

Exploitation

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

CVSS

6.1 · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Versions of https-proxy-agent prior to 2.2.3 are vulnerable to Machine-In-The-Middle. The package fails to enforce TLS on the socket if the proxy server responds the to the request with a HTTP status different than 200. This allows an attacker with access to the proxy server to intercept unencrypted communications, which may include sensitive information such as credentials. Recommendation Upgrade to version 3.0.0 or 2.2.3.

Published by the source

16 Apr 2020, 03:14 UTC

Last modified by the source

1 Nov 2023, 20:54 UTC

Source last checked

26 Oct 2026, 12:27 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-pc5p-h8pf-mvwp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-pc5p-h8pf-mvwp

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# Patch Next advisory brief: GHSA-pc5p-h8pf-mvwp

Advisory: Machine-In-The-Middle in https-proxy-agent
IDs: GHSA-pc5p-h8pf-mvwp
Record: https://patchnext.com/advisories/ghsa-pc5p-h8pf-mvwp (revision 2, source checked 26 Oct 2026, 12:27 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: https-proxy-agent 2.2.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm https-proxy-agent: affected < 2.2.3; fixed in 2.2.3

## Suggested inspection (read-only)
- `npm ls https-proxy-agent --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 https-proxy-agent.
- 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-pc5p-h8pf-mvwp (OSV record GHSA-pc5p-h8pf-mvwp lists affected ranges: npm https-proxy-agent >=0 <2.2.3 (fixed))
- Verified: https://github.com/advisories/GHSA-pc5p-h8pf-mvwp (GitHub-reviewed advisory GHSA-pc5p-h8pf-mvwp lists affected ranges: npm https-proxy-agent >=0 <2.2.3)

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