CVE-2026-18821

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-19. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker on the same network as a partition undergoing network boot can send a malformed packet, allowing arbitrary code to be executed in the partition firmware and compromising everything subsequently loaded by that partition. Other partitions and the managed system are not affected. Only partitions actively performing a network boot are affected, resulting in a confidentiality, integrity, and availability impact.

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 computed
Severity75% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

August 19, 2026

Last Modified

August 20, 2026

Advisory Details (1)

Auto-updated Aug 19, 2026
No patch confirmed yet.
generic

Security Bulletin: This Power System update is being released to address CVE-2026-18821

https://www.ibm.com/support/pages/node/7283232

Vendor Advisories for CVE-2026-18821(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 13× in last 7d / 13× 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. 2026-08-21 03:53 UTCEG score recompute
  2. 2026-08-21 03:52 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 16:36 UTCEG score recompute
  5. 2026-08-20 16:36 UTCGHSA enrichment
  6. 2026-08-20 16:07 UTCEG score recompute
  7. 2026-08-20 16:07 UTCGHSA enrichment
  8. 2026-08-20 13:25 UTCGHSA enrichment
  9. 2026-08-20 07:35 UTCEG score recompute
  10. 2026-08-20 07:35 UTCGHSA enrichment
  11. 2026-08-19 20:20 UTCEG score recompute
  12. 2026-08-19 19:58 UTCEG score recompute
  13. 2026-08-19 19:57 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18821?
CVE-2026-18821 is a high vulnerability published on August 19, 2026. IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker on the same network as a partition undergoing…
When was CVE-2026-18821 disclosed?
CVE-2026-18821 was first published in the National Vulnerability Database on August 19, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18821 actively exploited?
CVE-2026-18821 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 90.9% of all scored CVEs.
What is the CVSS score of CVE-2026-18821?
CVE-2026-18821 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-18821?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18821, 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

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