NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🐹
🐹 Go
Not in CISA KEV
MEDIUM severity

CVE-2021-40289 — mm-wiki

MEDIUM

CVE-2021-40289 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in github.com/phachon/mm-wiki. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

mm-wiki is vulnerable to Cross-Site Scripting (XSS)

Also known asGHSA-99g5-5643-xphp
Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
1 known
Exploitation data as of Oct 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-40289.

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk+0.02%
Lower risk than most CVEs44th percentile — riskier than 44% of all scored CVEsHighest risk
0.00%0.34%0.68%1.01%0.3%0.5%Apr 26Aug 26Oct 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
🐹github.com/phachon/mm-wiki

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

mm-wki v0.2.1 is vulnerable to Cross Site Scripting (XSS).

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/phachon/mm-wikiall versionsNo fix

Affected Products

1 product · 1 configurations
Application
mm-wkimm-wki_project
1 version
0.2.1
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.

mm-wki v0.2.1 is vulnerable to Cross Site Scripting (XSS).

github.comNVDNov 2022

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Remediation status

    The records we use list no patched version of github.com/phachon/mm-wiki for CVE-2021-40289. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    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.

Frequently Asked Questions

mm-wki v0.2.1 is vulnerable to Cross Site Scripting (XSS).
O3 Security · Impact-Aware SCA

Is CVE-2021-40289 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2021-40289: mm-wiki XSS (Medium 6.1)