html-template up to 1.25.9/1.26.2 on Go cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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3.4$0-$5k0.00

Summaryinfo

A vulnerability was found in html-template up to 1.25.9/1.26.2 on Go. It has been rated as problematic. Impacted is an unknown function. The manipulation leads to cross site scripting. This vulnerability is traded as CVE-2026-39823. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in html-template up to 1.25.9/1.26.2 on Go and classified as problematic. This issue affects an unknown function. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. The summary by CVE is:

CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a tag's attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the attribute, the escaper would fail to similarly escape it, leading to XSS.

The advisory is shared at go.dev. The identification of this vulnerability is CVE-2026-39823 since 04/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 313240 (Linux Distros Unpatched Vulnerability : CVE-2026-39823), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.25.10 or 1.26.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (313240), EUVD (EUVD-2026-28424) and CERT Bund (WID-SEC-2026-1437). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Google Container-Optimized OS
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Microsoft Azure Linux
  • IBM Business Automation Workflow
  • Golang Go
  • Red Hat OpenShift
  • Splunk Splunk Enterprise

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 313240
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-39823

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: html-template 1.25.10/1.26.3

Timelineinfo

04/07/2026 CVE reserved
05/07/2026 +30 days Advisory disclosed
05/07/2026 +0 days VulDB entry created
08/13/2026 +98 days VulDB entry last update

Sourcesinfo

Advisory: go.dev
Status: Confirmed

CVE: CVE-2026-39823 (🔒)
GCVE (CVE): GCVE-0-2026-39823
GCVE (VulDB): GCVE-100-361949
EUVD: 🔒
CERT Bund: WID-SEC-2026-1437 - Golang Go: Mehrere Schwachstellen

Entryinfo

Created: 05/07/2026 22:32
Updated: 08/13/2026 19:58
Changes: 05/07/2026 22:32 (53), 05/08/2026 00:05 (1), 05/09/2026 00:43 (2), 05/09/2026 01:00 (7), 06/19/2026 18:24 (1), 07/10/2026 09:43 (1), 07/20/2026 14:06 (1), 08/13/2026 19:58 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

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