Parse Server's Cloud function dispatch crashes server via prototype chain traversal

Description

Impact

Remote clients can crash the Parse Server process by calling a cloud function endpoint with a crafted function name that traverses the JavaScript prototype chain of a registered cloud function handler, causing a stack overflow.

Patches

The fix restricts property lookups during cloud function name resolution to own properties only, preventing prototype chain traversal from stored function handlers.

Workarounds

There is no known workaround.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-03-17 17:58:08 UTC
Updated
2026-03-19 21:12:42 UTC
GitHub reviewed
2026-03-17 17:58:08 UTC
NVD published
2026-03-18

EPSS Score

Score Percentile
0.03% 7.85%

CVSS Scores

Base score Version Severity Vector
8.2 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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:P)
Additional preconditions must be present for exploitation.
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:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High 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

CWEs

CWE id Name
CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Credits

  • fancymalware (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 >= 9.0.0, < 9.6.0-alpha.24 9.6.0-alpha.24
npm parse-server < 8.6.47 8.6.47

References

cvelogic Threat Intelligence