Page generated: 08 Nov 2026, 06:30 UTC
CVE-2021-31166
HTTP Protocol Stack Remote Code Execution Vulnerability
CVSS 9.8 (CRITICAL) KEV: KNOWN CATALOG
Attention and evidence
HYPE SCORE
0.0/10
REALITY · THREAT PRIORITY
9.0/10
General review priority; not probability
Evidence confidence: Exploitation recorded
Sources: 11 documents and public datasets.
Hype components
Headline sample (25%)
0/100
Press, 30 days (60%)
0/100
Grounded branding (15%)
0/100
HYPE TOTAL0/100
Sources and documents
Rapid7
Press · 18 Mar 2022, 07:00 · Metasploit Weekly Wrap-Up: Mar. 18, 2022 - Rapid7
GreyNoise
Press · 28 Jan 2022, 08:00 · Malicious Tag Roundup (January 2022) | Cybersecurity Blog - GreyNoise
BornCity
Press · 26 May 2021, 07:00 · Windows 10 21H1 reports ReleaseID 2009 - BornCity
SOC Prime
Press · 24 May 2021, 07:00 · Detect Wormable RCE Vulnerability (CVE-2021-31166) in Windows HTTP.sys - SOC Prime
SecurityWeek
Press · 18 May 2021, 07:00 · PoC Exploit Released for Wormable Windows Vulnerability - SecurityWeek
Score evolution
● Hype ● Reality
Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.
First record: hype 0.0 · reality 9.0 (2026-11-02 15:12). The curve appears once the score changes.
Public exploit evidence
4
Public exploit entries / repo candidates
Evidence context and dated references
Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.
Evidence in context
- Confidence in exploitation evidence
- Exploitation recorded
- Priority basis
- Recorded exploitation; CVSS 9.8; EPSS 99.9%
- Attention, last 30 days
- 0 distinct story titles; 0 press documents; 0 publisher domains.
- Technical potential
- network access, no prior privileges, no user interaction.
- Observed activity
- Exploitation recorded in CISA KEV.
- Known scale
- Not quantified.
- Evidence confidence basis
- Trusted exploitation confirmation
Score evaluated: 2026-11-05 13:58:26.907878+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z
Source event timeline
First press mention
11 May 2021, 07:00
Published
11 May 2021, 19:11
Latest press mention
18 Mar 2022, 07:00
Added to the CISA KEV catalog
06 Apr 2022, 00:00
Score calculated
05 Nov 2026, 13:58
PoCs on GitHub
4 repositories