Medium severity · published Jun 2, 2026
CVE-2026-42507
Arbitrary inputs are included in errors without any escaping in net/textproto
5.3
CVSS
0.4%
EPSS
No
On KEV
Description
When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
net/textproto · Go standard library
before 1.25.11; 1.26.0-0 before 1.26.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42507
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42507
go.dev
https://go.dev/cl/777060
go.dev
https://go.dev/issue/79346
groups.google.com
https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw
pkg.go.dev
https://pkg.go.dev/vuln/GO-2026-5039
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