VDB-389932 · CVE-2026-56858 · GCVE-0-2026-56858

Google html-template up to 1.25.12/1.26.5 cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.1	$0-$5k	1.01

Summaryinfo

A vulnerability was found in Google html-template up to 1.25.12/1.26.5 and classified as problematic. This issue affects some unknown processing. Executing a manipulation can lead to cross site scripting. This vulnerability is tracked as CVE-2026-56858. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Google html-template up to 1.25.12/1.26.5. It has been declared as problematic. This vulnerability affects an unknown code. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect integrity. CVE summarizes:

Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.

The advisory is shared for download at go.dev. This vulnerability was named CVE-2026-56858 since 06/23/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/14/2026). The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 1.25.13, 1.26.6 or 1.27.0-rc.3 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Google

Name

html-template

Version

License

free

Website

Vendor: https://www.google.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: html-template 1.25.13/1.26.6/1.27.0-rc.3

Timelineinfo

06/23/2026 CVE reserved
08/13/2026 +51 days VulDB entry created
08/14/2026 +0 days Advisory disclosed
08/14/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: google.com

Advisory: go.dev
Status: Confirmed

CVE: CVE-2026-56858 (🔒)
GCVE (CVE): GCVE-0-2026-56858
GCVE (VulDB): GCVE-100-389932

Entryinfo

Created: 08/14/2026 00:32
Changes: 08/14/2026 00:32 (53)
Complete: 🔍
Cache ID: 216::103