HTTP.sys Information Disclosure Vulnerability

published 2023-02-14 3 y ago modified 2026-08-19 2 mo ago also EUVD-2023-25854

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits: 0; none known

Patch / fix

fixed in 3 links 1

Microsoft Windows 11 version 21H2 10.0.22621.1574
Microsoft Windows 11 version 22H2 10.0.22621.1265
Microsoft Windows Server 2022 10.0.20348.1547

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21687 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-06-04)

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

Microsoft Windows 11 version 21H2
Microsoft Windows 11 version 22H2
Microsoft Windows Server 2022

Classification

Weakness

CWE-125 Out-of-bounds Read
CWE-668 Exposure of Resource to Wrong Sphere

References

msrc.microsoft.com /update-guide/vulnerability/CVE-2023-21687
vendor-advisory, patch

Sources

CVE List CVE-2023-21687
NVD CVE-2023-21687

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary