CVE-2026-27820

A flaw was found in zlib, a Ruby interface for the zlib compression/decompression library. The Zlib::GzipReader component contains a buffer overflow vulnerability. This occurs because the zstream_buffer_ungets function does not ensure sufficient memory capacity before moving existing data, which can lead to memory corruption. An attacker could potentially exploit this to cause unexpected behavior or system instability.

A buffer overflow vulnerability exists in the Zlib::GzipReader component of the Ruby zlib interface. This flaw, caused by insufficient memory capacity during data manipulation, could lead to memory corruption and system instability. This vulnerability is considered of a Moderate severity this happens because the high complexity to exploit, additionally the attacker may have not full control over the data is being corrupted or exfiltrated.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.