What is CVE-2023-3978?

CVE-2023-3978 is a medium-severity vulnerability in Golang Networking, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-08-02.

How severe is CVE-2023-3978?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2023-3978 known to be exploited?

5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Golang Networking

CVE-2023-3978

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-08-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (56.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Golang Networking
Golang.org/x/net Golang.org/x/net/html — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

go.dev/issue/61615 (Patch, Issue Tracking, Vendor Advisory)
go.dev/cl/514896 (Patch)
pkg.go.dev/vuln/GO-2023-1988 (Patch, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2023-3978?: CVE-2023-3978 is a medium-severity vulnerability in Golang Networking, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-08-02.
How severe is CVE-2023-3978?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2023-3978 known to be exploited?: 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.