CVE-2026-84411

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-03. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

The web management service in affected RouterOS versions contains an integer underflow in its HTTP request body handling that is reachable before authentication. This can be leveraged by an unauthenticated network attacker to achieve arbitrary code execution as root, or to cause a denial of service, using a single crafted request.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
59
EG Risk 59/100CISA SSVC

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 computed
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
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
0.9%
EPSS %ILE
59th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

October 2, 2026

Last Modified

October 3, 2026

Advisory Details (3)

Auto-updated Oct 3, 2026
Patch available. Sources: cisa.
cisa Patch Available

MikroTik RouterOS | CISA

https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-06
generic

MikroTik · Downloads

https://mikrotik.com/download
generic

CSAF/csaf_files/OT/white/2026/icsa-26-272-06.json at develop · cisagov/CSAF · GitHub

https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-06.json

Vendor Advisories for CVE-2026-84411(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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.

  1. 2026-10-04 09:08 UTCGHSA enrichment
  2. 2026-10-04 04:56 UTCGHSA enrichment
  3. 2026-10-04 00:45 UTCGHSA enrichment
  4. 2026-10-03 20:34 UTCGHSA enrichment
  5. 2026-10-03 16:23 UTCEG score recompute
  6. 2026-10-03 16:22 UTCGHSA enrichment
  7. 2026-10-03 16:10 UTCEG score recompute
  8. 2026-10-03 16:10 UTCGHSA enrichment
  9. 2026-10-03 14:26 UTCEPSS rescore
  10. 2026-10-03 12:01 UTCGHSA enrichment
  11. 2026-10-03 07:50 UTCGHSA enrichment
  12. 2026-10-03 03:38 UTCEG score recompute
  13. 2026-10-03 03:37 UTCGHSA enrichment
  14. 2026-10-02 23:26 UTCEG score recompute
  15. 2026-10-02 22:25 UTCEG score recompute
  16. 2026-10-02 22:25 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-84411?
CVE-2026-84411 is a critical vulnerability published on October 2, 2026. The web management service in affected RouterOS versions contains an integer underflow in its HTTP request body handling that is reachable before authentication. This can be leveraged by an unauthenticated network attacker to achieve arbitrary code execution as root, or to cause a denial of…
When was CVE-2026-84411 disclosed?
CVE-2026-84411 was first published on October 2, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84411 actively exploited?
CVE-2026-84411 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (59th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-84411?
CVE-2026-84411 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-84411?
A fix for CVE-2026-84411 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-84411 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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