Undirectional routing wasn't respected in some cases in Mitogen

published 2019-08-18 7 y ago modified 2026-06-17 4 mo ago also GHSA-8rf6-w2mx-4xjh , PYSEC-2019-104 , EUVD-2019-0086

cvss: 9.8; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.6%; EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits: 0; none known

core.py in Mitogen before 0.2.8 has a typo that drops the unidirectional-routing protection mechanism in the case of a child that is initiated by another child. The Ansible extension is unaffected. NOTE: the vendor disputes this issue because it is exploitable only in conjunction with hypothetical other factors, i.e., an affected use case within a library caller, and a bug in the message receiver policy code that led to reliance on this extra protection mechanism

Patch / fix

fixed in 2 links 1

pypi mitogen 0.2.8
networkgenomics mitogen 0.2.8

github.com/dw/mitogen@5924af1 commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-15149 updated 2025-11-21 cvss 5.3

mitogen: security bypass in core.py

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.65% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected packages

ecosystem	package	affected	fixed in
pypi	mitogen	<0.2.8	0.2.8

Classification

Weakness

CWE-254 7PK - Security Features

References

github.com /dw/mitogen/commit/5924af1566763e48c42028399ea0cd95c457b3dc
web, patch, third-party-advisory
mitogen.networkgenomics.com /changelog.html#v0-2-8-2019-08-18
web, release-notes
nvd.nist.gov /vuln/detail/CVE-2019-15149
advisory
github.com /dw/mitogen
package
github.com /pypa/advisory-database/tree/main/vulns/mitogen/PYSEC-2019-104.yaml
web
github.com /advisories/GHSA-8rf6-w2mx-4xjh
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary