CVE-2026-40871: mailcow: dockerized is an open source groupware/email suite based on docker

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HIGH 7.2WATCHLIST

CVE-2026-40871 is a high-severity flaw (CVSS 7.2) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint stores quarantine_category without validation or sanitization. This value is later used by quarantine_notify.py, which constructs SQL queries using unsafe % string formatting instead of parameterized queries. Th

Why this priority

High severity
EPSS top 5%: very likely to be exploited
CISA SSVC: public proof of concept
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	8.6% (top 5%)
CISA exploited list	No
Weakness	CWE-20, CWE-89, CWE-116, CWE-564
Published	2026-04-21
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-04-21 20:17 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · arm-none-eabi-binutils-cs · FIXED · 2.47-1.fc46 · FEDORA-2026-7498616952 · source

sudo dnf upgrade --advisory=FEDORA-2026-7498616952

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-r8fq-wrfm-cj2q

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40871?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-40871 being exploited?

CVE-2026-40871 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40871 affect?

CVE-2026-40871 affects affected software. Severity is high (CVSS 7.2). mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint s

How urgent is CVE-2026-40871?

Priority 57/100. High severity; EPSS top 5%: very likely to be exploited; CISA SSVC: public proof of concept; On your watchlist

Software pages

Docker vulnerabilities

References

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