CVE-2026-66140

Local privilege escalation via queue-name traversal

Published Jul 24, 2026 · Updated Jul 24, 2026

Directory traversal in Exim 4.88 through 4.99.4 allows local users with command-line access to gain privileges via queue-name arguments. The execution chain accepts queue-name transfer options from unprivileged callers and permits traversal characters, allowing access to files outside the spool directory. All installations are affected, but exploitation requires local command-line access; the documented consequence is privilege escalation.

CVSS severity8.4
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Directory traversal in Exim 4.88 through 4.99.4 allows local users with command-line access to gain privileges via queue-name arguments. The execution chain accepts queue-name transfer options from unprivileged callers and permits traversal characters, allowing access to files outside the spool directory. All installations are affected, but exploitation requires local command-line access; the documented consequence is privilege escalation.

The record

CVE
CVE-2026-66140
Published
Jul 24, 2026
Updated
Jul 24, 2026
Vendor
LibSPF2 Project
Product
Exim
Classifications
CWE-24, T1068
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.88 <4.99.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

LibSPF2 Project · Eximversion=4.88 <4.99.5

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.4MITRECVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-24Path Traversal: '../filedir'
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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