Vulnerability · Published May 22, 2026 · Assigned by Go

CVE-2026-27136Invoking duplicate attributes can cause XSS in golang.org/x/net/html

Medium 6.1

In plain English

A medium-severity security flaw in golang.org/x/net/html from golang.org/x/net. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.1Medium
Exploit odds (30 days)0.2%top 87.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10osbuild-composer165.1-5.el10_2.alma.1ALSA-2026:66432
AlmaLinux:9osbuild-composer165.1-5.el9_8.alma.1ALSA-2026:69293
AlmaLinux:10osbuild-composer-core165.1-5.el10_2.alma.1ALSA-2026:66432
AlmaLinux:9osbuild-composer-core165.1-5.el9_8.alma.1ALSA-2026:69293
AlmaLinux:10osbuild-composer-worker165.1-5.el10_2.alma.1ALSA-2026:66432
AlmaLinux:9osbuild-composer-worker165.1-5.el9_8.alma.1ALSA-2026:69293
AlmaLinux:9podman6:5.8.2-4.el9_8ALSA-2026:37123
AlmaLinux:9podman-docker6:5.8.2-4.el9_8ALSA-2026:37123
AlmaLinux:9podman-plugins6:5.8.2-4.el9_8ALSA-2026:37123
AlmaLinux:9podman-remote6:5.8.2-4.el9_8ALSA-2026:37123
AlmaLinux:9podman-tests6:5.8.2-4.el9_8ALSA-2026:37123
Debian:12golang-golang-x-netno fix listedDEBIAN-CVE-2026-27136
Debian:13golang-golang-x-netno fix listedDEBIAN-CVE-2026-27136
Debian:14golang-golang-x-net1:0.55.0-1DEBIAN-CVE-2026-27136
Gogolang.org/x/net0.55.0GO-2026-5030
Rocky Linux:10image-builder0:52.1-2.el10_2.rocky.0.1RLSA-2026:67139
Rocky Linux:9image-builder0:52.1-2.el9_8RLSA-2026:67138
Rocky Linux:10osbuild-composer0:165.1-5.el10_2.rocky.0.1RLSA-2026:66432
Rocky Linux:9osbuild-composer0:165.1-5.el9_8.rocky.0.1RLSA-2026:69293
Rocky Linux:10podman7:5.8.2-4.el10_2RLSA-2026:37072
Rocky Linux:9podman6:5.8.2-4.el9_8RLSA-2026:37123

Affected products (as reported)

VendorProductVersions
golang.org/x/net golang.org/x/net/html 0 – before 0.55.0

References