Bug 2506177

Summary: CVE-2026-16615 rest: weak random number generation in PKCE implementation [fedora-all]
Product: [Fedora] Fedora Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: restAssignee: Adrian Vovk <avovk>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: 45CC: avovk, cfergeau, gnome-sig, kalevlember
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["32817975-c882-4169-aab7-5176dd066bca"]}
Fixed In Version: rest-0.10.2-9.fc44 rest-0.10.2-5.fc43 rest-0.10.2-12.fc45 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-09-11 01:00:27 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: 2504432    

Description Guilherme de Almeida Suckevicz 2026-07-22 16:13:16 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.

A flaw was found in librest, affecting all versions. The PKCE implementation for OAuth authorization uses the GRand function from the GLib API, a cryptographically insecure pseudo-random number generator. Because the generated "code verifier" lacks sufficient cryptographic entropy, a malicious actor can reverse-engineer the pseudo-random number generator (PRNG) seed to predict or reconstruct the code verifier string, allowing an attacker to bypass PKCE protections and successfully impersonate the client during the OAuth 2.0 authorization flow.

Comment 1 Aoife Moloney 2026-08-17 15:35:57 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 2026-08-26 01:52:39 UTC
FEDORA-2026-c2116e108f (rest-0.10.2-5.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-c2116e108f

Comment 3 Fedora Update System 2026-08-26 01:52:40 UTC
FEDORA-2026-4baee57e28 (rest-0.10.2-12.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-4baee57e28

Comment 4 Adrian Vovk 2026-08-26 18:39:32 UTC
Not sure why the automation didn't mention it. But anyway, FEDORA-2026-df38653cf2 is the fix for Fedora 44

https://bodhi.fedoraproject.org/updates/FEDORA-2026-df38653cf2

Comment 5 Fedora Update System 2026-08-27 01:32:50 UTC
FEDORA-2026-c2116e108f 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-c2116e108f`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-c2116e108f

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

Comment 6 Fedora Update System 2026-08-27 01:55:18 UTC
FEDORA-2026-df38653cf2 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-df38653cf2`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-df38653cf2

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

Comment 7 Fedora Update System 2026-08-27 02:12:53 UTC
FEDORA-2026-4baee57e28 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-2026-4baee57e28`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-4baee57e28

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

Comment 8 Fedora Update System 2026-09-11 01:00:27 UTC
FEDORA-2026-df38653cf2 (rest-0.10.2-9.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 9 Fedora Update System 2026-09-11 01:26:30 UTC
FEDORA-2026-c2116e108f (rest-0.10.2-5.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 10 Fedora Update System 2026-09-11 18:49:39 UTC
FEDORA-2026-4baee57e28 (rest-0.10.2-12.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.