How severe is CVE-2023-3978?

CVE-2023-3978 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-3978?

CVE-2023-3978 affects the following packages: golang.org/x/net (Go). Ecosystems affected: Go.

How do I fix CVE-2023-3978?

Update golang.org/x/net to 0.13.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-3978 is resolved across your whole dependency graph.

How do I detect CVE-2023-3978 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-3978 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2023-3978 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-3978 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-3978?

CVE-2023-3978 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 58th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-3978?

CVE-2023-3978 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-3978 published, and has it been updated?

CVE-2023-3978 was published on August 2, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

CVE-2023-3978 — x/net

MEDIUM

CVE-2023-3978 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in golang.org/x/net. A fix is available for golang.org/x/net — see the affected versions and patch details below.

Improper rendering of text nodes in golang.org/x/net/html

Also known asGHSA-2wrh-6pvc-2jm9GO-2023-1988

Published

Aug 2, 2023

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-3978.

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs58th percentile — riskier than 58% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐹golang.org/x/net

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Text nodes not in the HTML namespace are incorrectly literally rendered, causing text which should be escaped to not be. This could lead to an XSS attack.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`golang.org/x/net`	all versions	0.13.0`go get golang.org/x/net@v0.13.0`

Affected Products

1 product · 1 configurations

Application

networkinggolang

< 0.13.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update golang.org/x/net to 0.13.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-3978 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Cryostat 2 on RHEL 8	`cryostat-tech-preview/cryostat-rhel8-operator:2.3.1-11`	RHSA-2023:6031
LVMS-4.14-RHEL-9	`lvms4/lvms-must-gather-rhel9:v4.14.1-3`	RHBA-2023:6863
Migration Toolkit for Virtualization 2.4	`migration-toolkit-virtualization/mtv-rhel8-operator:2.4.3-3`	RHBA-2023:6109
Red Hat Enterprise Linux 8	`container-tools:4.0-8090020230828093056.e7857ab1`	RHSA-2023:6938
Red Hat Enterprise Linux 8	`container-tools:rhel8-8090020230825121312.e7857ab1`	RHSA-2023:6939
Red Hat Enterprise Linux 9	`podman-2:4.6.1-5.el9`	RHSA-2023:6474
Red Hat Migration Toolkit for Containers 1.7	`rhmtc/openshift-migration-controller-rhel8:v1.7.13-4`	RHSA-2023:5888
Red Hat OpenShift Container Platform 4.12	`openshift4/ose-machine-api-operator:v4.12.0-202401190520.p0.g04504fb.assembly.stream`	RHSA-2024:0485

Frequently Asked Questions

Text nodes not in the HTML namespace are incorrectly literally rendered, causing text which should be escaped to not be. This could lead to an XSS attack.

O3 Security · Impact-Aware SCA

Is CVE-2023-3978 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

Timeline

Disclosed

Aug 2, 2023

Last updated

Oct 28, 2026

Identifiers

CVE-2023-3978

GHSA-2wrh-6pvc-2jm9

GO-2023-1988

References

Advisorygithub.com · CVE 2023 3978.json Advisorynvd.nist.gov · CVE 2023 3978 Webgo.dev Webgo.dev Webpkg.go.dev Webpkg.go.dev · GO 2023 1988

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting net are rated as high or higher (top: high).

CVE-2026-25680CVE-2025-22872CVE-2025-22870CVE-2023-45288CVE-2023-39325CVE-2023-44487CVE-2018-17846CVE-2022-41723

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026