Parse Server has denylist `requestKeywordDenylist` keyword scan bypass through nested object placement

CVE-2026-30938 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

The requestKeywordDenylist security control can be bypassed by placing any nested object or array before a prohibited keyword in the request payload. This is caused by a logic bug that stops scanning sibling keys after encountering the first nested value. Any custom requestKeywordDenylist entries configured by the developer are equally by-passable using the same technique.

All Parse Server deployments are affected. The requestKeywordDenylist is enabled by default.

Patches

The fix replaces the recursive object scanner with an iterative stack-based traversal that processes all nested values without prematurely exiting the scan loop. This also eliminates a potential stack overflow on deeply nested payloads.

Workarounds

Use a Cloud Code beforeSave trigger to validate incoming data for prohibited keywords across all classes.

References

  • GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-q342-9w2p-57fp
  • Fix Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.1-alpha.1
  • Fix Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.12

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-10 00:57:37 UTC
Updated
2026-03-10 18:44:49 UTC
GitHub reviewed
2026-03-10 00:57:37 UTC
NVD published
2026-03-10

EPSS Score

Score Percentile
0.06% 20.11%

CVSS Scores

Base score Version Severity Vector
6.9 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-q342-9w2p-57fp ↗
CVE CVE-2026-30938 ↗

CWEs

CWE id Name
CWE-693 Protection Mechanism Failure

Credits

  • 0xkakash1 (reporter)
  • mtrezza (coordinator)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm parse-server < 8.6.12 8.6.12 —
npm parse-server >= 9.0.0-alpha.1, < 9.5.1-alpha.1 9.5.1-alpha.1 —

References

cvelogic Threat Intelligence