CVE-2026-27820— zlib: Buffer Overflow in Zlib::GzipReader ungetc via large input leads to memory corruption
Get alerts for future matching vulnerabilitiesLog in to subscribe
I. Basic Information for CVE-2026-27820
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗ Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
zlib: Buffer Overflow in Zlib::GzipReader ungetc via large input leads to memory corruption
Source: NVD (National Vulnerability Database)
Vulnerability Description
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.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
未进行输入大小检查的缓冲区拷贝(传统缓冲区溢出)
Source: NVD (National Vulnerability Database)
Vulnerability Title
zlib 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
zlib是美国Mark Adler个人开发者的一个通用的数据压缩库。 zlib 3.0.0及以下版本、3.1.0版本、3.1.1版本、3.2.0版本和3.2.1版本存在安全漏洞，该漏洞源于Zlib::GzipReader存在缓冲区溢出，可能导致内存损坏。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-27820
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POCPremium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-27820
请登录查看更多情报信息。
IV. Related Vulnerabilities
Same vendor: ruby
- CVE-2026-42258
net-imap: Command Injection via unvalidated Symbol inputs - CVE-2026-42257
net-imap: Command Injection via "raw" arguments to multiple - CVE-2026-42256
net-imap: Denial of service via high iteration count for `SC - CVE-2026-42245
net-imap: Quadratic complexity when reading response literal - CVE-2026-42246
net-imap vulnerable to STARTTLS stripping via invalid respon
Same weakness: CWE-120
- CVE-2026-8260
D-Link DCS-935L HNAP Service hnap_service SetDeviceSettings - CVE-2026-8137
Totolink X5000R formDdns sub_458E40 buffer overflow - CVE-2026-6691
MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow - CVE-2026-7857
D-Link DI-8100 CGI user_group.asp sprintf buffer overflow - CVE-2026-7856
D-Link DI-8100 Web Management url_member.asp buffer overflow
V. Comments for CVE-2026-27820
No comments yet