CVE-2026-55778

LOW
INFO Priority: 0.01 BB Relevance: 44/100
Published: 2026-07-08 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: Passive
S: X
AT: Present
VC: None
VI: Low
VA: None

Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.9.1-alpha.11 and 8.6.81, the default fileUpload.fileExtensions blocklist could be bypassed by uploading a file with a non-standard or compound extension and dangerous content type, allowing storage adapters such as S3 and GCS to serve attacker-supplied active content and enable stored cross-site scripting. This issue is fixed in versions 9.9.1-alpha.11 and 8.6.81.

Weakness Classification (1)

Bug Bounty Relevance

44 / 100
✓ Network accessible
✓ Low complexity

CVSS Score

2.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.55%
Raw Score 0.005530
Percentile 46.1%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00553
2026-10-28
0.00553

Intelligence Sources

nvd ref →