CVE-2026-27820
- Source
- https://cve.org/CVERecord?id=CVE-2026-27820
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-27820.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2026-27820
- Aliases
- Downstream
- Related
- Published
- 2026-04-16T17:27:48.944Z
- Modified
- 2026-04-19T04:18:44.514326Z
- Severity
-
- 1.7 (Low) CVSS_V4 - 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 CVSS Calculator
- Summary
- zlib: Buffer Overflow in Zlib::GzipReader ungetc via large input leads to memory corruption
- Details
-
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 zstreambufferungets 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.
- Database specific
{ "cwe_ids": [ "CWE-120", "CWE-131" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27820.json", "cna_assigner": "GitHub_M" }- References
Affected packages
Git / github.com/ruby/zlib
Affected ranges
- Type
- GIT
- Repo
- https://github.com/ruby/zlib
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixedIntroducedFixedIntroducedFixed
- Database specific
{ "source": "AFFECTED_FIELD", "extracted_events": [ { "introduced": "0" }, { "fixed": "3.0.1" }, { "introduced": "3.1.0" }, { "fixed": "3.1.2" }, { "introduced": "3.2.0" }, { "fixed": "3.2.3" } ] }