CVE-2026-22184
zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname()
Description
zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression library. The flaw occurs when a user executes the untgz command with an excessively long archive name supplied via the command line, leading to an out-of-bounds write in a fixed-size global buffer.
INFO
Published Date :
Jan. 7, 2026, 9:16 p.m.
Last Modified :
Jan. 15, 2026, 2:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update zlib to version 1.3.1.3 or later.
- Recompile applications linked against the updated zlib.
- Validate untgz utility input for archive names.
- Avoid untrusted archive files.
Public PoC/Exploit Available at Github
CVE-2026-22184 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-22184.
| URL | Resource |
|---|---|
| https://github.com/madler/zlib | Product |
| https://seclists.org/fulldisclosure/2026/Jan/3 | Mailing List Third Party Advisory |
| https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname | Third Party Advisory |
| https://zlib.net/ | Product |
| https://github.com/madler/zlib/issues/1142 | Issue Tracking |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-22184 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-22184
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Dockerfile
Container monitoring platform on AWS using ECS Fargate, Terraform, and GitHub Actions. Built with OIDC-based CI/CD, tight IAM scoping, and deliberate cost and availability choices.
Dockerfile Nix Makefile Go JavaScript HTML Vue CSS HCL Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-22184 vulnerability anywhere in the article.
-
Daily CyberSecurity
CVE-2026-22184 (CVSS 9.3): Critical zlib Flaw Opens Door to Global Buffer Overflow
A critical vulnerability has been discovered in zlib, the lossless data-compression engine used on “virtually any computer hardware and operating system.” Tracked as CVE-2026-22184, this global buffer ... Read more
The following table lists the changes that have been made to the
CVE-2026-22184 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Jan. 15, 2026
Action Type Old Value New Value Added Tag disputed Changed Description zlib versions up to and including 1.3.1.2 contain a global buffer overflow in the untgz utility. The TGZfname() function copies an attacker-supplied archive name from argv[] into a fixed-size 1024-byte static global buffer using an unbounded strcpy() call without length validation. Supplying an archive name longer than 1024 bytes results in an out-of-bounds write that can lead to memory corruption, denial of service, and potentially code execution depending on compiler, build flags, architecture, and memory layout. The overflow occurs prior to any archive parsing or validation. zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression library. The flaw occurs when a user executes the untgz command with an excessively long archive name supplied via the command line, leading to an out-of-bounds write in a fixed-size global buffer. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/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 Removed CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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 Added CWE CWE-787 Removed CWE CWE-120 -
Initial Analysis by [email protected]
Jan. 14, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CPE Configuration OR *cpe:2.3:a:zlib:zlib:*:*:*:*:*:*:*:* versions up to (including) 1.3.1.2 Added Reference Type VulnCheck: https://github.com/madler/zlib Types: Product Added Reference Type CVE: https://github.com/madler/zlib/issues/1142 Types: Issue Tracking Added Reference Type VulnCheck: https://seclists.org/fulldisclosure/2026/Jan/3 Types: Mailing List, Third Party Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname Types: Third Party Advisory Added Reference Type VulnCheck: https://zlib.net/ Types: Product -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jan. 12, 2026
Action Type Old Value New Value Added Reference https://github.com/madler/zlib/issues/1142 -
New CVE Received by [email protected]
Jan. 07, 2026
Action Type Old Value New Value Added Description zlib versions up to and including 1.3.1.2 contain a global buffer overflow in the untgz utility. The TGZfname() function copies an attacker-supplied archive name from argv[] into a fixed-size 1024-byte static global buffer using an unbounded strcpy() call without length validation. Supplying an archive name longer than 1024 bytes results in an out-of-bounds write that can lead to memory corruption, denial of service, and potentially code execution depending on compiler, build flags, architecture, and memory layout. The overflow occurs prior to any archive parsing or validation. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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 Added CWE CWE-120 Added Reference https://github.com/madler/zlib Added Reference https://seclists.org/fulldisclosure/2026/Jan/3 Added Reference https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname Added Reference https://zlib.net/