CVE-2026-27820: zlib: Buffer Overflow in Zlib::GzipReader ungetc via large input leads to memory corruption

Overview

Severity
N/A
Exploit Status
Not Exploited
Patch Tuesday
2026-Apr
Released
2026-04-18
Last Updated
2026-05-06
EPSS Score
0.02% (percentile: 4.3%)

Affected Products (3)

Other

  • 21312-17084

Open Source Software

  • azl3 zlib 1.3.2-1 on Azure Linux 3.0
  • azl3 ruby 3.3.5-7 on Azure Linux 3.0

Revision History

  • 2026-04-18: Information published.
  • 2026-04-23: Information published.
  • 2026-04-23: Information published.
  • 2026-04-29: Information published.
  • 2026-05-06: Information published.