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CVE-2026-94439VulnerabilityPublished Updated

Microsoft · HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http

Affects MicrosoftSource GCVE Database

0
Authoritative record:CVE-2026-94439· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 1.27.2 or 1.26.9 soon.

Data as of 28 Oct 2026, 09:42 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 1.27.2, 1.26.9
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 8 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

Upgrade net/http to 1.27.2 or 1.26.9.

Affected software

ProductAffectedFixed in
Go standard librarynet/httpAffected
  • >=1.27.0-0 <1.27.2
Fixed in
  • 1.27.2
Go standard librarynet/httpAffected
  • <1.26.9
Fixed in
  • 1.26.9
Gonet/httppkg:golang/net/httpOther threatsAffected
  • <1.26.9
  • >=1.27.0-0 <1.27.2
Fixed in
  • 1.26.9
  • 1.27.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

CVE-2026-94439 is a vulnerability in the net/http component of Microsoft software version 3.0, involving HTTP/1 server connection desynchronization after a 2xx CONNECT response. The issue relates to improper handling of HTTP connections that may lead to desynchronization.

References

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