Cloudflare version of zlib library was found to be vulnerable to memory corruption issues affecting the deflation algorithm implementation (deflate.c). The issues resulted from improper input validation and heap-based buffer overflow.
A local attacker could exploit the problem during compression using a crafted malicious file potentially leading to denial of service of the software.
Patches: The issue has been patched in commit 8352d10 https://github.com/cloudflare/zlib/commit/8352d108c05db1bdc5ac3bdf834dad641694c13c . The upstream repository is not affected.
Severity
CVSS 3.1
5.5 medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-31)