Bug 2532266 (CVE-2026-89606)

Summary: CVE-2026-89606 kernel: ecryptfs: reject too-small tag 70 packets
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in ecryptfs, a component of the Linux kernel. This vulnerability allows a remote attacker to send a specially crafted tag 70 packet with a body smaller than expected. This can lead to an integer underflow during size calculation, potentially causing a denial of service (DoS) or system instability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-11 21:49:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ecryptfs: reject too-small tag 70 packets

ecryptfs_parse_tag_70_packet() subtracts fixed metadata fields from the
parsed packet body size to derive the encrypted filename size.  A
malformed packet with a body smaller than those fixed fields can underflow
that size calculation.

Reject tag 70 packets before the subtraction unless the body contains the
signature, cipher code, and at least one byte of encrypted filename data.
Comment 1 Keith Grant 2026-09-18 18:40:32 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89606.mbox