Medium severity · published May 7, 2026
CVE-2026-39826
Escaper bypass leads to XSS in html/template
6.1
CVSS
0.4%
EPSS
No
On KEV
Description
If a trusted template author were to write a <script> tag containing an empty 'type' attribute or a 'type' attribute with an ASCII whitespace, the execution of the template would incorrectly escape any data passed into the <script> block.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
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
HT
html/template · Go standard library
before 1.25.10; 1.26.0-0 before 1.26.3 · source: vendor
GO
GO · Golang
before 1.25.10; 1.26.0 before 1.26.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39826
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-39826
Patch
https://go.dev/cl/771180
Patch
https://go.dev/issue/78981
Release Notes
https://groups.google.com/g/golang-announce/c/qcCIEXso47M
Vendor Advisory
https://pkg.go.dev/vuln/GO-2026-4980
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