Bug 2494512

Summary:	CVE-2026-13676 python-jupytext: fast-uri: Security policy bypass due to improper Unicode hostname canonicalization [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Jon Moroney <jmoroney>
Component:	python-jupytext	Assignee:	Jerry James <loganjerry>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	45	CC:	loganjerry
Target Milestone:	---	Keywords:	Reopened, Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["a88e065f-ba4d-475c-97a1-bd24b4080d4f"]}
Fixed In Version:	python-jupytext-1.19.6-1.fc44 python-jupytext-1.19.6-1.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-10-14 01:21:11 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2494197

Description Jon Moroney 2026-06-29 16:59:53 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

fast-uri versions 2.3.1 through 3.1.2 and 4.0.0 fail to canonicalize Unicode (IDN) hostnames for HTTP-family URLs. The IDN conversion path calls a helper that does not exist on the global URL constructor, silently leaving the host in its original Unicode form while normalize() and equal() still return values that differ from a WHATWG-compatible URL parser. Applications that use fast-uri to enforce host-based policy (denylists, loopback filtering, redirect validation, outbound proxy routing) before passing the same URL to Node's URL or fetch can be bypassed when the two implementations resolve the same input to different hosts. Patches: upgrade to fast-uri 3.1.3 for the 3.x line or 4.0.1 for the 4.x line. Workarounds: enforce host policy using the same URL parser used for the actual request, or reject non-ASCII hosts before policy checks.

Comment 1 Aoife Moloney 2026-08-17 15:05:38 UTC

This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.

Comment 2 Fedora Update System 2026-10-05 19:44:28 UTC

FEDORA-2026-3942ab86fd (python-jupytext-1.19.6-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3942ab86fd

Comment 3 Fedora Update System 2026-10-06 01:23:40 UTC

FEDORA-2026-8b0bf60fcb has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-8b0bf60fcb`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8b0bf60fcb

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2026-10-06 01:56:41 UTC

FEDORA-2026-620e232420 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-620e232420`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-620e232420

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2026-10-06 02:26:20 UTC

FEDORA-2026-3942ab86fd has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-3942ab86fd`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-3942ab86fd

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-10-14 01:21:11 UTC

FEDORA-2026-620e232420 (python-jupytext-1.19.6-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 7 Fedora Update System 2026-10-14 01:30:17 UTC

FEDORA-2026-3942ab86fd (python-jupytext-1.19.6-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.