Microsoft · wc_PKCS7_DecodeEnvelopedData 1 byte out-of-bounds read
Affects MicrosoftSource GCVE Database
Not known to be exploited.
Data as of 27 Oct 2026, 00:10 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Exploitation evidence
Disclosed: evidence found.
CVE published 2 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Security Response Center Microsoft | Affected
| Fixed in– |
AI-suggested
Users should monitor official Microsoft advisories for updates and apply patches once released. Until then, no specific mitigation actions are documented.
Description
CVE-2026-4159 is a vulnerability involving a 1-byte out-of-bounds read in the wc_PKCS7_DecodeEnvelopedData function in Microsoft software versions 2.0 and 3.0. The vulnerability relates to improper memory access that could potentially lead to information disclosure or application instability.