Bug 2524564

Summary: CVE-2026-16599 wget1: wget: Denial of Service via crafted FTP OPIE/S-KEY authentication challenge [fedora-all]
Product: [Fedora] Fedora Reporter: Laura Pardo <lpardo>
Component: wget1Assignee: Michal Ruprich <mruprich>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: mruprich
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["426f627d-f54d-4f6a-b00a-a38ea148c132"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2523509    

Description Laura Pardo 2026-08-26 17:13:35 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.

GNU wget is vulnerable to denial of service in its FTP OPIE/S-KEY authentication functionality. The server-supplied sequence number from the FTP challenge line is used as an iteration count for an MD5 key-derivation loop without any upper bound validation. A malicious FTP server or a network attacker positioned to intercept FTP traffic can send a crafted OPIE challenge with a sequence number near INT_MAX, causing wget to perform up to approximately 2.1 billion MD5 computations and suspend for some time. The --timeout option does not mitigate this because it applies only to network I/O, not CPU computation.


This issue was fixed in commit e9697d98e7249b0f68a6be040a4f3dcc5bc101fa