VDB
ALPINE-CVE-2026-27820
ALPINE-CVE-2026-27820
PUBLISHED
CVSS 9.800000190734863 CRITICAL
zlib is a Ruby interface for the zlib compression/decompression library. Versions 3.0.0 and below, 3.1.0, 3.1.1, 3.2.0 and 3.2.1 contain a buffer overflow vulnerability in the Zlib::GzipReader. The zstream_buffer_ungets function prepends caller-provided bytes ahead of previously produced output but fails to guarantee the backing Ruby string has enough capacity before the memmove shifts the existing data. This can lead to memory corruption when the buffer length exceeds capacity. This issue has been fixed in versions 3.0.1, 3.1.2 and 3.2.3.
Risk Scores
CVSS 3.1
9.800000190734863
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Alpine:v3.24 | ruby | 0 |
| Alpine:v3.23 | ruby | 0, 3.3.3-r1, 3.3.3-r2 |
Timeline
- Apr 16, 2026 CVE Published
- Apr 30, 2026 Distribution Patch
- Jun 15, 2026 CVE Updated