Threat Intelligence / CVE / CVE-2020-0688

CVE-2020-0688 — Microsoft Exchange Server

CISA KEVRansomware

CVSS v3.1 8.8 (HIGH) · EPSS 94.3% (higher than 99.9% of all scored CVEs) · Priority 10/10 · Published 2020-02-11

As of 2025-10-29, CVE-2020-0688 is a HIGH-severity vulnerability in Microsoft Exchange Server, CVSS v3.1 8.8, EPSS 94.3% (99.9th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), with a US federal remediation deadline of 2022-05-03, and CISA links it to known ransomware campaigns. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2020-0688, most recently “MuddyWater Operation Olalampo — Iran MOIS-Nexus APT Deploys New Malware Variants with Telegram Bot C2 Targeting Middle Eastern Governments and Critical Infrastructure”.

Last updated: 2025-10-29

What is CVE-2020-0688?

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

The record classifies CVE-2020-0688 under weakness class CWE-287. 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. 6 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 2406 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
EPSS (FIRST): 94.3% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
CISA KEV: Listed since 2021-11-03, federal remediation deadline 2022-05-03 — used in known ransomware campaigns
Threadlinqs priority: 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
Published: 2020-02-11, last modified 2025-10-29

Is CVE-2020-0688 being exploited?

CISA added CVE-2020-0688 to the Known Exploited Vulnerabilities catalog on 2021-11-03, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2022-05-03 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 50 in the Threadlinqs vulnerability feed.

Affected products and versions

Microsoft: Exchange Server 2010, Exchange Server 2013, Exchange Server 2016, Exchange Server 2019

Showing 4 of 6 recorded product entries.

How to fix CVE-2020-0688

The record marks a vendor fix as available for CVE-2020-0688. Patch reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-0688. Vendor advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0688. Because CVE-2020-0688 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2022-05-03. 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-2020-0688

1 tracked threat in the Threadlinqs corpus references CVE-2020-0688, either in the campaign’s CVE list or as an indicator on the campaign record.

MuddyWater Operation Olalampo — Iran MOIS-Nexus APT Deploys New Malware Variants with Telegram Bot C2 Targeting Middle Eastern Governments and Critical Infrastructure — HIGH · 2026-02-28

Sources

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

Full detection coverage & IOCs for threats exploiting CVE-2020-0688 are available via the Threadlinqs MCP server (Purple tier). View plans →

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