CVE-2026-27820

Published: Apr 16, 2026 Last Modified: Apr 16, 2026
ExploitDB:
Other exploit source:
Google Dorks:
LOW 1,7
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

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.

120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability
Potential Impacts:
Modify Memory Execute Unauthorized Code Or Commands Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu)
Applicable Platforms
Languages: Assembly, C, C++, Memory-Unsafe
Likelihood of Exploit: High
View CWE Details
131

Incorrect Calculation of Buffer Size

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Availability Confidentiality
Potential Impacts:
Dos: Crash, Exit, Or Restart Execute Unauthorized Code Or Commands Read Memory Modify Memory
Applicable Platforms
Languages: C, C++, Memory-Unsafe
Likelihood of Exploit: High
View CWE Details
https://github.com/ruby/zlib/security/advisories/GHSA-g857-…
https://github.com/ruby/zlib/security/advisories/GHSA-g857-hhfv-j68w
https://hackerone.com/reports/3467067
https://hackerone.com/reports/3467067