CVE-2025-47911

Description

The html.Parse function in golang.org/x/net/html has quadratic parsing complexity when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
google-guest-agent	25.10 questing	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
containerd	25.10 questing	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
golang-golang-x-net-dev	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
adsys	25.10 questing	Not affected
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
juju-core	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	16.04 LTS xenial	Needs evaluation
lxd	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
golang-golang-x-net	25.10 questing	Vulnerable
	24.04 LTS noble	Fixed 1:0.21.0+dfsg-1ubuntu0.1~esm2
	22.04 LTS jammy	Fixed 1:0.0+git20211209.491a49a+dfsg-1ubuntu0.1~esm2

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Notes

octagalland

google-guest-agent, adsys, juju-core and lxd contain a vendored copy of golang-golang-x-net

mdeslaur

containerd contains a vendored copy of golang-golang-x-net adsys doesn't appear to use html.Parse, marking as not-affected google-guest-agent doesn't appear to use html.Parse, marking as not-affected containerd doesn't appear to use x/net/html, marking as not-affected.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
golang-golang-x-net	Upstream: 59706cd

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	Low
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

Related Ubuntu Security Notices (USN)

USN-8089-1
Go Networking vulnerabilities
12 March 2026