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🐹
🐹 Go
Not in CISA KEV
HIGH severity

CVE-2018-17143 — x/net

HIGH

CVE-2018-17143 is a high-severity (CVSS 7.5) Buffer Overflow vulnerability in golang.org/x/net. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for golang.org/x/net — see the affected versions and patch details below.

golang.org/x/net/html has Improper Restriction of Operations within the Bounds of a Memory Buffer

Also known asGO-2022-0193
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
2.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs86th percentile — riskier than 86% of all scored CVEsHighest risk
0.00%1.14%2.28%3.42%0.6%2.8%May 26Sep 26Nov 26

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

The html package (aka x/net/html) through 2018-09-17 in Go mishandles <template><tBody><isindex/action=0>, leading to a "panic: runtime error" in inBodyIM in parse.go during an html.Parse call.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogolang.org/x/netall versions0.0.0-20180921000356-2f5d2388922fgo get golang.org/x/net@v0.0.0-20180921000356-2f5d2388922f

Affected Products

2 products · 3 configurations
OS
fedorafedoraproject
2 versions
2829
Application
netgolang
≤ 2018-09-17
range
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The html package (aka x/net/html) through 2018-09-17 in Go mishandles <t…

github.comNVDAug 2020

Detection & mitigation playbook

Open-source dependency

  1. 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.

  2. Fix

    Update golang.org/x/net to 0.0.0-20180921000356-2f5d2388922f or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-17143 is resolved across your whole dependency graph.

  3. Workarounds

    Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Frequently Asked Questions

The html package (aka x/net/html) through 2018-09-17 in Go mishandles <template><tBody><isindex/action=0>, leading to a "panic: runtime error" in inBodyIM in parse.go during an html.Parse call
O3 Security · Impact-Aware SCA

Is CVE-2018-17143 in your dependencies?

Find it across Go, including transitive dependencies.

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CVE-2018-17143: x/net — Fix Available