Bug 2510815 (CVE-2026-69249)

Summary: CVE-2026-69249 python-cryptography: python-cryptography: Duplicate self-signed intermediates can cause exponential path-building
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in python-cryptography. When processing invalid certificate chains that include duplicate self-signed certificates, the system recursively invokes the same certificate, leading to an exponential increase in processing time. A remote attacker could exploit this by providing a specially crafted certificate chain, causing resource exhaustion and a denial of service (DoS) condition, making the system unavailable. The integrity of the system's validation is not affected, only its availability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-03 22:02:50 UTC 
python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 49.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.