CVE-2026-18727

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-08-13. the CNA's CVSS baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:redhat, epss, ghsa
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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 computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 18, 2026

Advisory Details (2)

Auto-updated Aug 12, 2026
Patch available. Sources: redhat.
redhat

2462956 – (CVE-2026-18727) CVE-2026-18727 open-iscsi: open-iscsi: Integer underflow in iscsiuio DHCPv6 parsing

https://bugzilla.redhat.com/show_bug.cgi?id=2462956
redhat Patch Available

CVE-2026-18727 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-18727

Vendor Advisories for CVE-2026-18727(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 22× in last 7d / 34× 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. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 11:25 UTCEG score recompute
  3. 2026-08-20 11:25 UTCGHSA enrichment
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 13:08 UTCGHSA enrichment
  6. 2026-08-18 14:52 UTCEG score recompute
  7. 2026-08-18 14:52 UTCGHSA enrichment
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-18 12:44 UTCGHSA enrichment
  10. 2026-08-17 14:10 UTCEG score recompute
  11. 2026-08-17 14:10 UTCGHSA enrichment
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-16 15:53 UTCEG score recompute
  14. 2026-08-16 15:53 UTCGHSA enrichment
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 02:14 UTCEPSS rescore
  17. 2026-08-15 17:36 UTCEG score recompute
  18. 2026-08-15 17:36 UTCGHSA enrichment
  19. 2026-08-15 01:30 UTCEPSS rescore
  20. 2026-08-14 19:18 UTCGHSA enrichment
  21. 2026-08-14 18:39 UTCEG score recompute
  22. 2026-08-14 18:39 UTCGHSA enrichment
  23. 2026-08-13 22:00 UTCEPSS rescore
  24. 2026-08-13 20:22 UTCEG score recompute
  25. 2026-08-13 20:22 UTCGHSA enrichment
Show 9 more
  1. 2026-08-13 19:47 UTCEG score recompute
  2. 2026-08-13 19:47 UTCGHSA enrichment
  3. 2026-08-13 04:20 UTCEG score recompute
  4. 2026-08-13 04:20 UTCGHSA enrichment
  5. 2026-08-13 03:31 UTCEG score recompute
  6. 2026-08-13 03:31 UTCGHSA enrichment
  7. 2026-08-12 22:21 UTCEG score recompute
  8. 2026-08-12 21:21 UTCEG score recompute
  9. 2026-08-12 21:20 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-18727?
CVE-2026-18727 is a medium vulnerability published on August 12, 2026. A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing. Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length…
When was CVE-2026-18727 disclosed?
CVE-2026-18727 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18727 actively exploited?
CVE-2026-18727 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 90.2% of all scored CVEs.
What is the CVSS score of CVE-2026-18727?
CVE-2026-18727 has a CVSS v4.0 base score of 6.5 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-18727?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18727, 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-2026-18727

Explore →

Is Your Infrastructure Affected by CVE-2026-18727?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs