New 'ShieldCrash' Zero-Day Exploit Targets Microsoft Defender
C SecurityWeek ·
Admiralty grading (A–F · 1–6)
Source reliability
- A Completely reliable
- B Usually reliable
- C Fairly reliable
- D Not usually reliable
- E Unreliable
- F Cannot be judged
Information credibility
- 1 Confirmed
- 2 Probably true
- 3 Possibly true
- 4 Doubtful
- 5 Improbable
- 6 Cannot be judged
NATO Admiralty (AJP-2.1) grades confidence, independent of the risk score. Cross-source corroboration isn't tracked for non-CVE news, so single-source items are capped at a lower credibility number; a low number does not imply low quality.
Key insight
The ShieldCrash exploit enables privilege escalation to System privileges on Windows systems with September 2026 patches and has publicly available PoC code.
Description
A zero-day exploit named 'ShieldCrash' has been publicly released by security researcher Nightmare Eclipse and targets fully patched Windows systems. The exploit demonstrates arbitrary file access with System privileges and enables full privilege escalation. The proof-of-concept code is publicly available on GitHub, significantly increasing the risk of widespread exploitation. The exploit functions against systems with September 2026 patches, affecting a large number of Windows environments in enterprises.
Risk score
- cvss base
- 45.00
- kev bonus
- 0.00
- epss bonus
- 0.00
- poc bonus
- 15.00
- raw before weight
- 60.00
- industry weight
- 1.21
- freshness factor
- 1.00
- exploitability factor
- 1.00
- days old
- 0.00
- vendor mismatch penalty
- 0.00
- consensus penalty
- -3.00
Path: operational
Consensus check
The pipeline self-checks before delivery. These rules lowered the score:
-
TTP_SKIPPEDTTP mapping skipped (placeholder or aggregation article) −3
- Consensus penalty:
- −3.0
- Total penalty:
- −3.0