No exploitation reportedFix available

CVE-2026-40606

Q: Is CVE-2026-40606 actively exploited?

Active exploitation of CVE-2026-40606 has not been confirmed. Its EPSS score was 0.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-40606?

CVE-2026-40606 has a CVSS v3 base score of 4.8 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

No exploitation reported by the sources we read.

Published2026-04-21
Fixed in12.2.2
WeaknessCWE-90

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2026-04-2118:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-40606?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-40606?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Mitmproxy

Branch	Affected	Fixed in	Source
12.2	< 12.2.2	12.2.2	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Mitmproxy to 12.2.2

Advisories and patches

github.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2026-04-22
OpenCVESSVC decisionnone—
CNACVSS 3.14.8read 2026-10-23
CNAweakness (CWE)CWE-90read 2026-10-23
FIRST EPSSEPSS score0.3 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Published: 2026-04-21
Last Modified: 2026-06-17
NVD status: Analyzed

Frequently asked questions

What is CVE-2026-40606?

Is CVE-2026-40606 actively exploited?

Active exploitation of CVE-2026-40606 has not been confirmed. Its EPSS score was 0.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-40606?

CVE-2026-40606 has a CVSS v3 base score of 4.8 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Running mitmproxy? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database