All vulnerabilities
CVE-2026-94440

Memory limit bypass when parsing MIME headers in net/textproto, mime/multipart

Go standard library net/textproto
Open in ThreatlineRecord JSON
CVSS
7.5High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.40%Chance of exploitation activity in the next 30 days, higher than 33% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.26.9Also 1.27.2CVE List
Published8 Oct 2026Updated 9 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

Parsing a multipart form can bypass memory limits and read an arbitrarily long line into memory when the remaining limit at the start of a part is less than 400 bytes.

Text from CVE List

Affected versions 4

  • net/textprotoaffected: all versions before 1.26.9CVE List
  • net/textprotoaffected: 1.27.0-0 before 1.27.2CVE List
  • mime/multipartaffected: all versions before 1.26.9CVE List
  • mime/multipartaffected: 1.27.0-0 before 1.27.2CVE List

References 4