CVE search · CVE-2026-27820
CVE-2026-27820
low 1.7
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.
Details
- Status
- Analyzed
- Published
- Last changed
- Source
- security-advisories@github.com
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 4.0 | low 1.7 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
security-advisories@github.comSecondary |
| CVSS 3.1 | critical 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
nvd@nist.govPrimary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
- ruby-lang · zlib
References
- https://github.com/ruby/zlib/security/advisories/GHSA-g857-hhfv-j68wVendor Advisory
- https://hackerone.com/reports/3467067Permissions Required