What is GHSA-q76j-gcg9-vxc6?

Hugo's default code-block renderer wrote the Markdown code-fence language / info-string into the ` ` wrapper without HTML escaping. A fence info-string containing a quote and a ` ` payload breaks out of the attribute and injects a live script element. This is not an issue if you fully trust every file under /content and every content adapter you load.

How severe is GHSA-q76j-gcg9-vxc6?

No CVSS score has been assigned to GHSA-q76j-gcg9-vxc6 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-q76j-gcg9-vxc6?

GHSA-q76j-gcg9-vxc6 affects the following packages: github.com/gohugoio/hugo (Go). Ecosystems affected: Go.

How do I fix GHSA-q76j-gcg9-vxc6?

Update github.com/gohugoio/hugo to 0.163.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q76j-gcg9-vxc6 is resolved across your whole dependency graph.

How do I detect GHSA-q76j-gcg9-vxc6 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/gohugoio/hugo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-q76j-gcg9-vxc6 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-q76j-gcg9-vxc6?

O3 pinpoints whether GHSA-q76j-gcg9-vxc6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-q76j-gcg9-vxc6 actively exploited in the wild?

No public exploit code has been indexed for GHSA-q76j-gcg9-vxc6 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 GHSA-q76j-gcg9-vxc6?

GHSA-q76j-gcg9-vxc6 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th 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 GHSA-q76j-gcg9-vxc6?

GHSA-q76j-gcg9-vxc6 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 GHSA-q76j-gcg9-vxc6 published, and has it been updated?

GHSA-q76j-gcg9-vxc6 was published on June 19, 2026 and was last updated on July 24, 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

GHSA-q76j-gcg9-vxc6

GHSA-q76j-gcg9-vxc6 is a Cross-site Scripting (XSS) vulnerability in github.com/gohugoio/hugo. O3 Security confirms whether GHSA-q76j-gcg9-vxc6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Hugo: XSS via unescaped code-fence language in default code block renderer

Also known asCVE-2026-58402GO-2026-5569

Published

Jun 19, 2026

Updated

Jul 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 12, 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 GHSA-q76j-gcg9-vxc6.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs23th percentile — riskier than 23% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

🐹github.com/gohugoio/hugo

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

Hugo's default code-block renderer wrote the Markdown code-fence language / info-string into the <code class="language-…" data-lang="…"> wrapper without HTML escaping. A fence info-string containing a quote and a <script> payload breaks out of the attribute and injects a live script element.

This is not an issue if you fully trust every file under /content and every content adapter you load.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/gohugoio/hugo`	≥ 0.60.0&&< 0.163.3	0.163.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/gohugoio/hugo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/gohugoio/hugo to 0.163.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q76j-gcg9-vxc6 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-q76j-gcg9-vxc6 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-q76j-gcg9-vxc6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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

RHSA-2026:36862Red Hat Hardened Images

Frequently Asked Questions

Hugo's default code-block renderer wrote the Markdown code-fence language / info-string into the `<code class="language-…" data-lang="…">` wrapper without HTML escaping. A fence info-string containing a quote and a `<script>` payload breaks out of the attribute and injects a live script element. This is not an issue if you fully trust every file under /content and every content adapter you load.

O3 Security · Impact-Aware SCA

Is GHSA-q76j-gcg9-vxc6 in your dependencies?

O3 detects GHSA-q76j-gcg9-vxc6 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works