ruby zlib vulnerabilities

Latest ruby zlib CVEs

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

   Published 2026-04-16

   Low·CVSS 1.7 PoC

   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...

Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.