cookie-signature Timing Attack

Exploitation

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

CVSS

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

EPSS

• CVE-2016-1000236: 0.90% estimated exploitation activity in the next 30 days; percentile 59.61 (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.

Affected versions of cookie-signature are vulnerable to timing attacks as a result of using a fail-early comparison instead of a constant-time comparison. Timing attacks remove the exponential increase in entropy gained from increased secret length, by providing per-character feedback on the correctness of a guess via miniscule timing differences. Under favorable network conditions, an attacker can exploit this to guess the secret in no more than charsetlength guesses, instead of charset^length guesses required were the timing attack not present. Recommendation Update to 1.0.4 or later.

Published by the source

6 Jan 2020, 18:44 UTC

Last modified by the source

8 Nov 2023, 03:58 UTC

Source last checked

26 Oct 2026, 12:16 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-92vm-wfm5-mxvv

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-92vm-wfm5-mxvv

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2016-1000236

Advisory: cookie-signature Timing Attack
IDs: CVE-2016-1000236, GHSA-92vm-wfm5-mxvv
Record: https://patchnext.com/advisories/cve-2016-1000236 (revision 2, source checked 26 Oct 2026, 12:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: cookie-signature 1.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm cookie-signature: affected < 1.0.4; fixed in 1.0.4

## Suggested inspection (read-only)
- `npm ls cookie-signature --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 cookie-signature.
- 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-92vm-wfm5-mxvv (OSV record GHSA-92vm-wfm5-mxvv lists affected ranges: npm cookie-signature >=0 <1.0.4 (fixed))
- Verified: https://github.com/advisories/GHSA-92vm-wfm5-mxvv (GitHub-reviewed advisory GHSA-92vm-wfm5-mxvv lists affected ranges: npm cookie-signature >=0 <1.0.4)

Commands are suggestions: review each one before running it.