CVE-2022-41040 — Microsoft Exchange Server

As of 2025-10-21, CVE-2022-41040 is a HIGH-severity vulnerability in Microsoft Exchange Server, CVSS v3.1 8.8, EPSS 94.1% (99.9th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-09-30), with a US federal remediation deadline of 2022-10-21, and CISA links it to known ransomware campaigns. Threadlinqs Intelligence links 3 tracked threat campaigns to CVE-2022-41040, most recently “FamousSparrow APT Targets Azerbaijani Oil & Gas Sector via ProxyShell/ProxyNotShell Exchange Exploitation”.

Last updated: 2025-10-21

What is CVE-2022-41040?

Microsoft Exchange Server Elevation of Privilege Vulnerability

The record classifies CVE-2022-41040 under weakness class CWE-918. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1441 days ago.

Severity and exploitation probability

CVSS v3.1 base score

8.8 — HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C

EPSS (FIRST)

94.1% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs

CISA KEV

Listed since 2022-09-30, federal remediation deadline 2022-10-21 — used in known ransomware campaigns

Threadlinqs priority

10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum

Published

2022-10-03, last modified 2025-10-21

Is CVE-2022-41040 being exploited?

CISA added CVE-2022-41040 to the Known Exploited Vulnerabilities catalog on 2022-09-30, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-10-21 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

Affected products and versions

• Microsoft: Exchange Server

How to fix CVE-2022-41040

The record marks a vendor fix as available for CVE-2022-41040. Patch reference: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-41040. Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-41040. Because CVE-2022-41040 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-10-21. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2022-41040

3 tracked threats in the Threadlinqs corpus reference CVE-2022-41040, either in the campaign’s CVE list or as an indicator on the campaign record.

• FamousSparrow APT Targets Azerbaijani Oil & Gas Sector via ProxyShell/ProxyNotShell Exchange Exploitation — CRITICAL · 2026-08-23
• FamousSparrow APT Targets Azerbaijani Oil & Gas Industry via Exchange ProxyShell/ProxyNotShell (Deed RAT, Terndoor, Mofu Loader) — CRITICAL · 2026-06-10
• FamousSparrow APT Multi-Wave Intrusion at Azerbaijani Oil & Gas Company — Evolved Two-Stage DLL Sideloading Delivers Deed RAT (0xFF66ABCD) and Terndoor via Mofu Loader — CRITICAL · 2026-05-13

Sources

Seeded from cveorg and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

• msrc.microsoft.com

← all vulnerabilities · Markdown version · Threadlinqs Intelligence