CVE-2021-41163

CRITICALNVD 10.010.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 10.0 under NVD CVSS v3. EPSS exploit probability: 19.8%, top 3% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekElevated
10.0
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 20%CVSS: 10.0Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Discourse is an open source platform for community discussion. In affected versions maliciously crafted requests could lead to remote code execution. This resulted from a lack of validation in subscribe_url values. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. To workaround the issue without updating, requests with a path starting /webhooks/aws path could be blocked at an upstream proxy.

CVSS v3
10.0
EG Score
10.0(medium)
EG Risk
66(Track*)
EG Risk 66/100SSVC: Track*

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity100% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Watch closely — could escalate to Attend.
EPSS
97.1%
KEV
Not listed

Published

October 20, 2021

Last Modified

November 21, 2024

Advisory Details (2)

Auto-updated Jul 18, 2026
Patch available. Sources: github_commit, github.
github Patch Available

RCE via malicious SNS subscription payload · Advisory · discourse/discourse · GitHub

https://github.com/discourse/discourse/security/advisories/GHSA-jcjx-pvpc-qgwq
github_commit

commit fa3c46cf079d (discourse/discourse)

Fix landed in discourse/discourse commit fa3c46cf079d — awaiting tagged release

https://github.com/discourse/discourse/commit/fa3c46cf079d28b086fe1025349bb00223a5d5e9

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 14:16 UTCEPSS rescore
  2. 2026-07-23 02:04 UTCEG score recompute
  3. 2026-07-22 22:50 UTCEG score recompute
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Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCibrahmsql/CVE-2021-41163
    First seen Jul 5, 2025
    Open source ↗
  • GitHub PoCibrahmsql/discourse-CVE-2021-41163
    First seen Jul 5, 2025
    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-41163?
CVE-2021-41163 is a critical vulnerability published on October 20, 2021. Discourse is an open source platform for community discussion. In affected versions maliciously crafted requests could lead to remote code execution. This resulted from a lack of validation in subscribe_url values. This issue is patched in the latest stable, beta and tests-passed versions of…
When was CVE-2021-41163 disclosed?
CVE-2021-41163 was first published in the National Vulnerability Database on October 20, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-41163 actively exploited?
CVE-2021-41163 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-41163?
CVE-2021-41163 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2021-41163?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-41163, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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