Usermin through 2.570 OS Command Injection via Read Mail IMAP Folder Deletion
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Usermin version 2.570 or earlier Read Mail module enabled Mail server operating in IMAP mode
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 16/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Usermin, a web-based mail and system administration tool, contains an OS command injection flaw in its Read Mail module that lets a logged-in user run commands as their system account. The attack is carried out remotely over the network with low-privilege login, and it involves creating an IMAP folder with shell metacharacters in its name from an external mail client and then deleting that folder in Usermin.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
Usermin through 2.570 contains an OS command injection vulnerability in the Read Mail module that allows authenticated users to execute commands through unsanitized IMAP folder names. Attackers can create a folder containing shell metacharacters via an external IMAP client, then delete it in Usermin to run commands as their system account, bypassing webmail-only restrictions.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.7/10CVSS 7.7
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 23 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Usermin version 2.570 or earlier Read Mail module enabled Mail server operating in IMAP modeApply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- webmin usermin
through 2.570
Evidence 6
- Patch
- Report
- Repository
- Repository
- Link
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123620
Is CVE-2026-123620 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Usermin's Read Mail module passes a folder name into an operating system command when a mail folder is deleted over IMAP. A user can use this to run commands as the system account that runs Usermin, even where the account is meant to be webmail-only.Source: vulncheck.com, hackmd.io
Which versions are affected by CVE-2026-123620?
usermin: through 2.570.Source: cve.now feed data
Am I affected, and how do I check?
Usermin through version 2.570 is affected when the Read Mail module is enabled and the mail server operates in IMAP mode. To check, look at the installed Usermin version and confirm whether Read Mail is enabled in the Usermin module settings.Source: vulncheck.com, hackmd.io
How do I fix CVE-2026-123620?
No fixed version is listed in the facts provided, so there is no confirmed upgrade target. Check the Webmin/Usermin project for a release newer than 2.570 that carries the fix.Source: vulncheck.com, hackmd.io