Threat Intelligence / CVE / CVE-2021-44026

CVE-2021-44026 — Roundcube Webmail

CISA KEV
CVSS v3.1 9.8 (CRITICAL) · EPSS 64.0% (higher than 98.4% of all scored CVEs) · Priority 9/10 · Published 2021-11-19

As of 2025-11-04, CVE-2021-44026 is a CRITICAL-severity vulnerability in Roundcube Webmail, CVSS v3.1 9.8, EPSS 64.0% (98.4th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-06-22), with a US federal remediation deadline of 2023-07-13. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2021-44026, most recently “Russia (GRU Unit 26165 / APT28) Runs Multi-Vector Surveillance, Intimidation, Sabotage and Cyber Espionage Campaign Against Europe's Ukraine Defence Supply Chain”.

Last updated: 2025-11-04

What is CVE-2021-44026?

Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to a potential SQL injection via search or search_params.

The record classifies CVE-2021-44026 under weakness class CWE-89. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 6 affected-product entries are recorded, across 3 vendors, listed below. The identifier was first published 1759 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
64.0% probability of exploitation in the next 30 days, higher than 98.4% of all scored CVEs
CISA KEV
Listed since 2023-06-22, federal remediation deadline 2023-07-13
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2021-11-19, last modified 2025-11-04

Is CVE-2021-44026 being exploited?

CISA added CVE-2021-44026 to the Known Exploited Vulnerabilities catalog on 2023-06-22, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2023-07-13 under BOD 22-01. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2021-44026

The record marks a vendor fix as available for CVE-2021-44026. Patch reference: https://github.com/roundcube/roundcubemail/commit/ee809bde2dcaa04857a919397808a7296681dcfa. Vendor advisory: https://bugs.debian.org/1000156. Because CVE-2021-44026 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2023-07-13. 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-2021-44026

2 tracked threats in the Threadlinqs corpus reference CVE-2021-44026, either in the campaign’s CVE list or as an indicator on the campaign record.

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-2021-44026 are available via the Threadlinqs MCP server (Purple tier). View plans →

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