CyberSecBulletin
CVE-2026-49103NVD status: Deferred

Webmin: Path Traversal: '../filedir'

CVE-2026-49103 is a critical-severity path traversal: '../filedir' vulnerability in Webmin, with a CVSS 4.0 base score of 9.4 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.640 as the first without the flaw, so updating Webmin to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Webmin to 2.640 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
WebminWebminbefore 2.6402.640

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
HighSerious loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
HighSerious loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
HighSerious loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (mitre.org).

Official description

Webmin before 2.640 does not safely construct a filename for saving of an attachment within the mailboxes component. This occurs in mailboxes/detachall.cgi.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Path Traversal: '../filedir'

The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize../ sequences that can resolve to a location that is outside of that directory.

How developers prevent this class of flaw

  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More Path Traversal: '../filedir' vulnerabilities (CWE-24)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Webmin

All Webmin vulnerabilities

Recent Path Traversal: '../filedir' vulnerabilities

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