Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
HIGH severity

GHSA-pj27-2xvp-4qxg — @fastify/session

HIGHFix: fastify/session@0495ce5

GHSA-pj27-2xvp-4qxg is a high-severity (CVSS 7.4) CWE-613 vulnerability in @fastify/session. A fix is available for @fastify/session — see the affected versions and patch details below.

@fastify/session reuses destroyed session cookie

Also known asCVE-2024-35220
Published
May 21, 2024
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for GHSA-pj27-2xvp-4qxg.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs36th percentile — riskier than 36% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-pj27-2xvp-4qxg by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 379,842 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

48other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
@fastify/sessionnpm
243Kdownloads / week

Description

Impact

When restoring the cookie from the session store, the expires field is overriden if the maxAge field was set. This means a cookie is never correctly detected as expired and thus expired sessions are not destroyed.

Patches

Updating to v10.9.0 will solve this.

Workarounds

None

References

Publicly reported at: https://github.com/fastify/session/issues/251

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npm@fastify/sessionall versions10.9.0npm install @fastify/session@10.9.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @fastify/session, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update @fastify/session to 10.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pj27-2xvp-4qxg is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Impact When restoring the cookie from the session store, the `expires` field is overriden if the `maxAge` field was set. This means a cookie is never correctly detected as expired and thus expired sessions are not destroyed. ### Patches Updating to v10.9.0 will solve this. ### Workarounds None ### References Publicly reported at: https://github.com/fastify/session/issues/251
O3 Security · Impact-Aware SCA

Is GHSA-pj27-2xvp-4qxg in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works
GHSA-pj27-2xvp-4qxg: @fastify/session | O3 Security