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.
CVE-2026-22184
“▲” beside the score: it is higher than NVD's CVSS score.
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-01-07. NVD baseline CVSS 7.8; sources differ by 2.0.
Also known asEUVD-2026-1173 (ENISA EUVD) · GHSA-7687-3v4j-49fr (GitHub Security Advisories)Source: ENISA EUVD
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
A fix is available — apply it.
- CVSS v3
- 7.8
- EG Score
- 9.8CRITICALmedium confidence
- EG Risk
- 75EG Risk 75/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity98% × 45%Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.4%
- EPSS %ILE
- 35th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
January 7, 2026
Last Modified
September 1, 2026
Advisory Details (8)
Auto-updated Jun 30, 2026Affected: Red Hat Enterprise Linux 10",
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22184.json2427688 – (CVE-2026-22184) CVE-2026-22184 zlib: zlib: Arbitrary code execution via buffer overflow in untgz utility
https://bugzilla.redhat.com/show_bug.cgi?id=2427688cve-details
https://access.redhat.com/security/cve/CVE-2026-22184contrib/ungtz: Buffer Overflow in TGZfname() via Unbounded strcpy() on User-Supplied Archive Name · Issue #1142 · madler/zlib · GitHub
https://github.com/madler/zlib/issues/1142zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname() | Advisories | VulnCheck
https://www.vulncheck.com/advisories/zlib-untgz-global-buffer-overflow-in-tgzfnameFull Disclosure: zlib v1.3.1.2 Global Buffer Overflow in TGZfname() of zlib untgz Utility via Unbounded strcpy() on User-Supplied Archive Name
https://seclists.org/fulldisclosure/2026/Jan/3GitHub - madler/zlib: A massively spiffy yet delicately unobtrusive compression library. · GitHub
https://github.com/madler/zlibVendor Advisories for CVE-2026-22184(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(9 across 9 ecosystems)
Alpine:v3.20(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| zlib | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 21× in last 7d / 78× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 99 of 253 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 154 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 17:53 UTCEG score recompute
- 2026-11-01 17:53 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-31 19:15 UTCEG score recompute
- 2026-10-31 19:15 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-30 20:35 UTCEG score recompute
- 2026-10-30 20:35 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-29 21:57 UTCEG score recompute
- 2026-10-29 21:57 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-28 23:20 UTCEG score recompute
- 2026-10-28 23:19 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-28 00:39 UTCEG score recompute
- 2026-10-28 00:39 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-27 01:58 UTCEG score recompute
- 2026-10-27 01:58 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-25 23:20 UTCEG score recompute
- 2026-10-25 23:20 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-25 14:42 UTCEG score recompute
Show 74 moreShow fewer
- 2026-10-25 00:39 UTCEG score recompute
- 2026-10-25 00:39 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-24 02:01 UTCEG score recompute
- 2026-10-24 02:01 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-23 03:23 UTCEG score recompute
- 2026-10-23 03:23 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-22 04:42 UTCEG score recompute
- 2026-10-22 04:41 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-21 05:58 UTCEG score recompute
- 2026-10-21 05:58 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-20 07:19 UTCEG score recompute
- 2026-10-20 07:19 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-19 08:39 UTCEG score recompute
- 2026-10-19 08:38 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-18 09:58 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-18 03:55 UTCEG score recompute
- 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-17 06:41 UTCEG score recompute
- 2026-10-17 06:41 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-16 07:54 UTCEG score recompute
- 2026-10-16 07:54 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-15 06:54 UTCEG score recompute
- 2026-10-15 06:54 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-14 02:40 UTCEG score recompute
- 2026-10-14 02:40 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-12 22:51 UTCEG score recompute
- 2026-10-12 22:51 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-12 16:22 UTCEG score recompute
- 2026-10-12 09:20 UTCGHSA enrichmentGHSA-7687-3v4j-49fr · GitHub severity CRITICAL · GitHub CVSS 9.8
- 2026-10-11 20:04 UTCEG score recompute
- 2026-10-11 17:17 UTCEG score recompute
- 2026-10-11 14:49 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-10 02:55 UTCOSV refresh
- 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-29 15:21 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-24 14:03 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-20 12:21 UTCOSV refresh
- 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
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Same product
10 shownAlpine:v3.20:zlib · Alpine:v3.21:zlib · Debian:11:zlib
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- CVE-2026-85091EG 7.4HIGH
- CVE-2023-45853EG 9.8CRITICAL
- CVE-2016-9843EG 9.8EPSS p93CRITICAL
- CVE-2016-9841EG 9.8EPSS p95CRITICAL
- CVE-2016-9842EG 8.8EPSS p92HIGH
- CVE-2016-9840EG 8.8EPSS p92HIGH
- CVE-2005-2096EG 7.5EPSS p93HIGH
Frequently asked(5)
What is CVE-2026-22184?
When was the CVE record for CVE-2026-22184 published?
Is CVE-2026-22184 actively exploited?
What is the CVSS score of CVE-2026-22184?
How do I remediate CVE-2026-22184?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-22184
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