MikroTik RouterOS before 7.24 contains a heap memory corruption vulnerability in the userspace SMB daemon that allows remote attackers to corrupt adjacent heap memory by supplying a crafted uniPwdLen value in the SMB1 SessionSetupAndX handler. An attacker can send a malformed SMB1 request with a uniPwdLen field that triggers an integer underflow, causing the resulting value to be used as the copy length in a memory copy operation into a smaller heap buffer, corrupting adjacent heap memory.
CVE-2026-89028
HIGHPre-NVD 7.57.5—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-16. a secondary CVSS source baseline 7.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(high)
- EG Risk
- 34(Track)EG Risk 34/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation1% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 45%
- KEV
- Not listed
Published
September 16, 2026
Last Modified
September 17, 2026
Advisory Details (2)
Auto-updated Sep 16, 2026No patch confirmed yet.
generic
MikroTik RouterOS < 7.24 Heap Corruption via SMB1 SessionSetupAndX | Advisories | VulnCheck
https://www.vulncheck.com/advisories/mikrotik-routeros-heap-corruption-via-smb1-sessionsetupandxgeneric
7.24 [stable] is released! - Announcements - MikroTik community forum
https://forum.mikrotik.com/t/7-24-stable-is-released/272381Vendor Advisories for CVE-2026-89028(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 16× in last 7d / 16× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.
- 2026-09-19 09:32 UTCGHSA enrichment
- 2026-09-18 21:14 UTCEG score recompute
- 2026-09-18 21:14 UTCGHSA enrichment
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 08:41 UTCGHSA enrichment
- 2026-09-17 20:28 UTCEG score recompute
- 2026-09-17 20:28 UTCGHSA enrichment
- 2026-09-17 19:32 UTCEPSS rescore
- 2026-09-17 19:31 UTCEG score recompute
- 2026-09-17 19:31 UTCGHSA enrichment
- 2026-09-17 14:53 UTCGHSA enrichment
- 2026-09-17 02:39 UTCEG score recompute
- 2026-09-17 02:39 UTCGHSA enrichment
- 2026-09-16 14:24 UTCEG score recompute
- 2026-09-16 13:27 UTCEG score recompute
- 2026-09-16 13:25 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-191 · CWE-122
- CVE-2007-0063EG 10.0EPSS p97HIGH
- CVE-2016-9603NVD 5.5EG 9.9EPSS p91CRITICAL
- CVE-2017-20241EG 9.8CRITICAL
- CVE-2006-10003EG 9.8CRITICAL
- CVE-2006-10002NVD 7.5EG 9.8CRITICAL
- CVE-2018-11930EG 9.8CRITICAL
- CVE-2014-9187EG 9.8CRITICAL
- CVE-2018-14618NVD 7.5EG 9.8EPSS p96CRITICAL
- CVE-2016-8622NVD 3.7EG 9.8EPSS p91CRITICAL
- CVE-2018-14353EG 9.8CRITICAL
Frequently asked(5)
What is CVE-2026-89028?
CVE-2026-89028 is a high vulnerability published on September 16, 2026. MikroTik RouterOS before 7.24 contains a heap memory corruption vulnerability in the userspace SMB daemon that allows remote attackers to corrupt adjacent heap memory by supplying a crafted uniPwdLen value in the SMB1 SessionSetupAndX handler. An attacker can send a malformed SMB1 request with a…
When was CVE-2026-89028 disclosed?
CVE-2026-89028 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89028 actively exploited?
CVE-2026-89028 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 54.8% of all scored CVEs.
What is the CVSS score of CVE-2026-89028?
CVE-2026-89028 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-89028?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-89028, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-89028
Is Your Infrastructure Affected by CVE-2026-89028?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.