CVE-2026-40606 | ProxyAuth Addon LDAP Injection in mitmproxy

mitmproxy is a interactive TLS-capable intercepting HTTP proxy for penetration testers and software developers and mitmweb is a web-based interface for mitmproxy. In mitmproxy 12.2.1 and below, the builtin LDAP proxy authentication does not correctly sanitize the username when querying the LDAP server. This allows a malicious client to bypass authentication. Only mitmproxy instances using the proxyauth option with LDAP are affected. This option is not enabled by default. The vulnerability has been fixed in mitmproxy 12.2.2 and above.

Published: 2026-04-21 Last update: 2026-04-24 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40606 is rated Low Risk (27.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.08%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-40606

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-13 0.03% 0.08% +0.05%
2 2026-04-22 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40606

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 2.5 [email protected]

Weakness enumeration for CVE-2026-40606

GitHub Security Advisory for CVE-2026-40606

GHSA-527g-3w9m-29hv · Severity: medium · Ecosystem: pip — mitmproxy has an LDAP Injection

OS Trackers for CVE-2026-40606

vendor priority summary link
debian not yet assigned CVE-2026-40606 not yet assigned priority: Debian including 1 source packages (mitmproxy), 4 status rows across 4 suites (bookworm, bullseye, forky, sid): open 4. https://security-tracker.debian.org/tracker/CVE-2026-40606
ubuntu medium CVE-2026-40606 medium priority: Ubuntu including 1 source packages (mitmproxy), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, resolute, upstream, xenial): needs-triage 8. https://ubuntu.com/security/CVE-2026-40606

Affected software / configurations for CVE-2026-40606

Vendor Product Version Raw CPE
mitmproxy mitmproxy < 12.2.2 cpe:2.3:a:mitmproxy:mitmproxy:*:*:*:*:*:*:*:*

References for CVE-2026-40606

cvelogic Threat Intelligence