Incorrect Calculation of Buffer Size Affecting rubygem-json package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-RHEL7-RUBYGEMJSON-17223706
  • published7 Jun 2026
  • disclosed16 Apr 2026

Introduced: 16 Apr 2026

CVE-2026-27820  (opens in a new tab)
CWE-131  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:7 rubygem-json.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rubygem-json package and not the rubygem-json package as distributed by RHEL. See How to fix? for RHEL:7 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1