Bug 2500852 - CVE-2026-15812 kronosnet: kronosnet: access control list bypass via link ID spoofing on unencrypted dynamic links [fedora-all]
Summary: CVE-2026-15812 kronosnet: kronosnet: access control list bypass via link ID s...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Fedora
Classification: Fedora
Component: kronosnet
Version: rawhide
Hardware: Unspecified
OS: Unspecified
low
low
Target Milestone: ---
Assignee: Fabio Massimo Di Nitto
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["a52bea26-85dc-4674-8061-8...
Depends On:
Blocks: CVE-2026-15812
TreeView+ depends on / blocked
 
Reported: 2026-07-15 10:49 UTC by Ganesh
Modified: 2026-07-20 14:01 UTC (History)
3 users (show)

Fixed In Version: kronosnet-1.35-1.fc45
Clone Of:
Environment:
Last Closed: 2026-07-20 14:01:56 UTC
Type: ---
Embargoed:


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Description Ganesh 2026-07-15 10:49:50 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.

Vulnerability Reference: A flaw was found in kronosnet's dynamic link validation process where it fails to safely verify packet origins, permitting an access control list (ACL) bypass via ID spoofing.

Component / Vulnerable Part: kronosnet -> Access Control List (ACL) engine for dynamic link handling (https://github.com/kronosnet/kronosnet/).

Technical Analysis & Root Cause: When kronosnet is configured to utilize dynamic links (allowing connections from any source IP address), it relies on an internal ACL structure mapped to internal link identifiers. A logical flaw exists within the dynamic packet processing pipeline where the authentication routine implicitly trusts the incoming frame's source payload metadata to determine the link ID. The validation logic does not cryptographically or cryptanalytically challenge the source identifier. Consequently, an adversary can craft network packets with a spoofed link ID matching an authorized node context, tricking the parser into circumventing ACL constraints.

Impact: A remote, unauthenticated attacker can exploit this flow to inject arbitrary data packets directly into the kronosnet interface. Depending on how the upper-layer application processes unexpected or untrusted data, this can trigger packet corruption or structural runtime instability.

Comment 2 Fedora Update System 2026-07-20 13:57:51 UTC
FEDORA-2026-3e85d87212 (kronosnet-1.35-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3e85d87212

Comment 3 Fedora Update System 2026-07-20 14:01:56 UTC
FEDORA-2026-3e85d87212 (kronosnet-1.35-1.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.


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