zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname()
Summary
| CVE | CVE-2026-22184 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-01-07 21:16:01 UTC |
| Updated | 2026-06-30 03:17:26 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 4.6 MEDIUM from [email protected]
CVSS:4.0/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
EPSS: 0.003500000 probability, percentile 0.269480000 (date 2026-07-01)
Problem Types: CWE-787 | CWE-120 | CWE-787 CWE-787 Out-of-bounds Write | CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 4.6 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 4.6 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | ADP | CVSS | 8.6 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 8.6 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/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
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zlib Software | Zlib | affected 1.3.1.2 custom | Not specified |
| ADP | Red Hat | Logging Subsystem For Red Hat OpenShift | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OpenJDK 1.8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OpenJDK 11 ELS | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OpenJDK 17 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OpenJDK 21 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Build Of OpenJDK 25 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat JBoss Core Services | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenStack Platform 16.2 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenStack Platform 17.1 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| zlib.net | [email protected] | zlib.net | Product |
| github.com/madler/zlib | [email protected] | github.com | Product |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-22184 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| github.com/madler/zlib/issues/1142 | af854a3a-2127-422b-91ae-364da2661108 | github.com | Issue Tracking |
| www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfname | [email protected] | www.vulncheck.com | Third Party Advisory |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22184.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| seclists.org/fulldisclosure/2026/Jan/3 | [email protected] | seclists.org | Mailing List, Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Ron Edgerson (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-01-07T21:02:32.602Z | Reported to Red Hat. |
| ADP | 2026-01-07T20:25:19.892Z | Made public. |
Workarounds
ADP: To mitigate this vulnerability, avoid using the `untgz` utility with untrusted archive names or from untrusted sources. System administrators should ensure that any automated processes or user interactions involving `untgz` validate the length of archive names to prevent triggering the buffer overflow. If the `untgz` utility is not essential for system operation, consider restricting its execution permissions or removing the package that provides it, if applicable.