How severe is CVE-2026-33538?

No CVSS score has been assigned to CVE-2026-33538 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-33538?

CVE-2026-33538 affects the following packages: parse-server (npm), parse-server (npm). Ecosystems affected: npm.

How do I fix CVE-2026-33538?

Update parse-server to 9.6.0-alpha.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33538 is resolved across your whole dependency graph.

How do I detect CVE-2026-33538 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-2026-33538 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-33538 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33538 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-2026-33538?

CVE-2026-33538 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 38th 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-2026-33538?

CVE-2026-33538 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-33538 published, and has it been updated?

CVE-2026-33538 was published on March 24, 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-2026-33538 — parse-server

Fix: parse-community/parse-server@40eb442

CVE-2026-33538 is a Uncontrolled Resource Consumption vulnerability in parse-server. A fix is available for parse-server — see the affected versions and patch details below.

Parse Server: Denial of service via unindexed database query for unconfigured auth providers

Also known asBIT-parse-2026-33538GHSA-g4cf-xj29-wqqr

Published

Mar 24, 2026

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-2026-33538.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.01%

Lower risk than most CVEs38th percentile — riskier than 38% 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

50Kdownloads / week

Description

Impact

An unauthenticated attacker can cause Denial of Service by sending authentication requests with arbitrary, unconfigured provider names. The server executes a database query for each unconfigured provider before rejecting the request, and since no database index exists for unconfigured providers, each request triggers a full collection scan on the user database. This can be parallelized to saturate database resources.

Patches

The fix validates that an authentication provider is configured before executing any database query. Requests with unconfigured providers are now rejected immediately without querying the database.

Workarounds

There is no known workaround other than upgrading.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`parse-server`	≥ 9.0.0&&< 9.6.0-alpha.52	9.6.0-alpha.52`npm install parse-server@9.6.0-alpha.52`
📦npm	`parse-server`	all versions	8.6.58`npm install parse-server@8.6.58`

Affected Products

1 product · 53 configurations

Application

parse-serverparseplatform

≥ 9.0.0 && < 9.6.0

1 version

9.6.0

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 9.6.0-alpha.52 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33538 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Impact An unauthenticated attacker can cause Denial of Service by sending authentication requests with arbitrary, unconfigured provider names. The server executes a database query for each unconfigured provider before rejecting the request, and since no database index exists for unconfigured providers, each request triggers a full collection scan on the user database. This can be parallelized to saturate database resources. ### Patches The fix validates that an authentication provider is configured before executing any database query. Requests with unconfigured providers are now rejecte

O3 Security · Impact-Aware SCA

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