CVE-2026-87776

HIGH CVSS 3.1: 7.5 EPSS 0.36%
Updated Sep 11, 2026
Express
Parameter Value
CVSS 7.5 (HIGH)
Affected Versions before 1.8.2
Fixed In 1.8.2
Type CWE-459, CWE-401 (Memory Leak)
Vendor Express
Public PoC No

compression is a Node.js and Express compression middleware. In versions before 1.8.2, when a client aborts the connection while a compressed response is still being sent, the zlib stream created to compress that response is never destroyed, so each aborted compressed response leaks its native zlib memory. A remote unauthenticated attacker can repeatedly open requests and disconnect early, exhausting the available memory and crashing the server.

All applications using compression are affected. The issue is fixed in compression 1.8.2, and users should upgrade to 1.8.2 or later.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v3.1