CVE-2026-43503

A flaw was found in the Linux kernel's networking (skbuff) component. When skb_try_coalesce() attaches paged fragments, it can lose the SKBFL_SHARED_FRAG marker. This can lead to the Encapsulating Security Payload (ESP) input decrypting data in place over page-cache backed fragments, potentially resulting in data corruption.

Impact is rated as Important because the privileged file-backed cache pages may be modified through a shared-page ownership bypass. Within Red Hat Enterprise Linux and Red Hat OpenShift Container Platform, this vulnerability was fixed at the same time as CVE-2026-46300.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

See the security bulletin for a detailed mitigation procedure.