How severe is CVE-2026-34363?

No CVSS score has been assigned to CVE-2026-34363 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-34363?

CVE-2026-34363 affects the following packages: parse-server (npm), parse-server (npm). Ecosystems affected: npm.

How do I fix CVE-2026-34363?

Update parse-server to 9.7.0-alpha.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34363 is resolved across your whole dependency graph.

How do I detect CVE-2026-34363 in my npm dependencies?

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

How do I mitigate CVE-2026-34363 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.

Is CVE-2026-34363 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-34363 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.

What is the EPSS score for CVE-2026-34363?

CVE-2026-34363 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-34363?

CVE-2026-34363 is classified as CWE-362 (CWE-362). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-34363 published, and has it been updated?

CVE-2026-34363 was published on March 31, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-34363 — parse-server

Fix: parse-community/parse-server@5834e29

CVE-2026-34363 is a CWE-362 vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.

Parse Server: LiveQuery protected field leak via shared mutable state across concurrent subscribers

Also known asBIT-parse-2026-34363GHSA-m983-v2ff-wq65

Published

Mar 31, 2026

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34363.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk-0.02%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

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

Real-World Exposure

2 pkgs 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.

62other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

parse-servernpm

82Kdownloads / week

Description

Impact

When multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object.

Additionally, when an afterEvent Cloud Code trigger is registered, one subscriber's trigger modifications can leak to other subscribers through the same shared mutable state.

Any Parse Server deployment using LiveQuery with protected fields or afterEvent triggers is affected when multiple clients subscribe to the same class.

Patches

The fix deep-clones the shared objects at the start of each subscriber's processing callback, ensuring each subscriber works on an independent copy. Additionally, a bug was fixed where master key LiveQuery clients could not receive events on classes with protected fields due to an incorrect type passed to the sensitive data filter.

Workarounds

There is no known workaround.

Resources

GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-m983-v2ff-wq65
Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10330
Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10331

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`parse-server`	≥ 9.0.0&&< 9.7.0-alpha.9	9.7.0-alpha.9`npm install parse-server@9.7.0-alpha.9`
📦npm	`parse-server`	all versions	8.6.65`npm install parse-server@8.6.65`

Affected Products

1 product · 10 configurations

Application

parse-serverparseplatform

≥ 9.0.0 && < 9.7.0

1 version

9.7.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for parse-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update parse-server to 9.7.0-alpha.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34363 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.

Frequently Asked Questions

### Impact When multiple clients subscribe to the same class via LiveQuery, the event handlers process each subscriber concurrently using shared mutable objects. The sensitive data filter modifies these shared objects in-place, so when one subscriber's filter removes a protected field, subsequent subscribers may receive the already-filtered object. This can cause protected fields and authentication data to leak to clients that should not see them, or cause clients that should see the data to receive an incomplete object. Additionally, when an afterEvent Cloud Code trigger is registered, one

O3 Security · Impact-Aware SCA

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