Bug 2506827 (CVE-2026-64208)

Summary: CVE-2026-64208 kernel: crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
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 the Linux kernel's `krb5` crypto library and `AF_RXRPC` component. This vulnerability arises from a lack of proper length checks before decrypting or verifying incoming messages. A remote attacker could exploit this by sending specially crafted messages, leading to a Denial of Service (DoS) condition where the system becomes unavailable.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-07-24 16:06:45 UTC
In the Linux kernel, the following vulnerability has been resolved:

crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks

Change the krb5 crypto library to provide facilities to precheck the length
of the message about to be decrypted or verified.

Fix AF_RXRPC to make use of this to validate DATA packets secured with
RxGK.

Comment 1 Mauro Matteo Cascella 2026-07-28 12:38:11 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072411-CVE-2026-64208-5d8d@gregkh/T