Vulnerability in Compression

CVE-2026-87776

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (40.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-87776: held from 0.006 to 0.005.

EPSS over last 30 days · oldest: 0.006 · newest: 0.005 · change: -0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-87776?
CVE-2026-87776 is a high-severity vulnerability in Compression, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-09-11.
How severe is CVE-2026-87776?
High severity. CVSS v3 base score is 7.5 out of 10.