How severe is GHSA-5mrq-x3x5-8v8f?

GHSA-5mrq-x3x5-8v8f has a CVSS score of 6.8/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-5mrq-x3x5-8v8f?

GHSA-5mrq-x3x5-8v8f affects the following packages: jupyter-server (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-5mrq-x3x5-8v8f?

Update jupyter-server to 2.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5mrq-x3x5-8v8f is resolved across your whole dependency graph.

How do I detect GHSA-5mrq-x3x5-8v8f in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyter-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-5mrq-x3x5-8v8f if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-5mrq-x3x5-8v8f?

O3 pinpoints whether GHSA-5mrq-x3x5-8v8f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-5mrq-x3x5-8v8f actively exploited in the wild?

No public exploit code has been indexed for GHSA-5mrq-x3x5-8v8f yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-5mrq-x3x5-8v8f published, and has it been updated?

GHSA-5mrq-x3x5-8v8f was published on May 5, 2026 and was last updated on June 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-5mrq-x3x5-8v8f

MEDIUM

GHSA-5mrq-x3x5-8v8f is a medium-severity (CVSS 6.8) vulnerability in jupyter-server. O3 Security confirms whether GHSA-5mrq-x3x5-8v8f is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Jupyter Server's Authentication Cookies Remain Valid After Password Reset and Server Restart

Also known asCVE-2026-40934PYSEC-2026-69

Published

May 5, 2026

Updated

Jun 6, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

🐍jupyter-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A persistent cookie secret vulnerability allows authenticated users to maintain indefinite access even after password changes.

The cookie secret used to sign authentication cookies is stored in a permanent file (~/.local/share/jupyter/runtime/jupyter_cookie_secret) that is never automatically rotated or cleared, allowing stolen or compromised cookies to remain valid indefinitely regardless of password resets.

PoC

Start a Jupyter server with password authentication: jupyter server password, jupyter server
Log in with the password and capture the authentication cookie (e.g., just login with a browser).
Change the password to revoke access: jupyter server password
Restart the server
Use the old stolen cookie => remains valid and provides full authenticated access.

Impact

All jupyter-server deployments using password authentication where security incidents may occur
Multi-user systems where one user's compromised session should be revocable by administrators
Shared or public-facing Jupyter servers where credential rotation is a security requirement
Any deployment where password changes are expected to revoke existing sessions

Patches

Jupyter Server 2.18+

Workaround

rm ~/.local/share/jupyter/runtime/jupyter_cookie_secret
# Then restart the server

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`jupyter-server`	all versions	2.18.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jupyter-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update jupyter-server to 2.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5mrq-x3x5-8v8f is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-5mrq-x3x5-8v8f is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-5mrq-x3x5-8v8f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary A persistent cookie secret vulnerability allows authenticated users to maintain indefinite access even after password changes. The cookie secret used to sign authentication cookies is stored in a permanent file (`~/.local/share/jupyter/runtime/jupyter_cookie_secret`) that is never automatically rotated or cleared, allowing stolen or compromised cookies to remain valid indefinitely regardless of password resets. ## PoC - Start a Jupyter server with password authentication: `jupyter server password`, `jupyter server` - Log in with the password and capture the authentication cooki

O3 Security · Impact-Aware SCA

Is GHSA-5mrq-x3x5-8v8f in your dependencies?

O3 detects GHSA-5mrq-x3x5-8v8f across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works