In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg This improves the fix for CVE-2026-43500. Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent) then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains unmodified. This has an additional advantage in that the packet is then arranged in the buffer with the correct alignment required for the crypto algorithms to process directly. The performance of the crypto does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much - possibly due to removing complexity from the I/O thread. Yet another advantage is that the I/O thread doesn't have to copy packets which would slow down packet distribution, ACK generation, etc.. The buffer belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket, but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a subsequent recvmsg(). Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to using USHRT_MAX to indicate an invalid offset. Note also that I would generally prefer to replace the buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to have to allocate a new sk_buff.

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg This improves the fix for     CVE-2026-43500. Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally     by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the     packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent)     then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains     unmodified. This has an additional advantage in that the packet is then arranged in the buffer with the     correct alignment required for the crypto algorithms to process directly. The performance of the crypto     does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much
    - possibly due to removing complexity from the I/O thread. Yet another advantage is that the I/O thread     doesn't have to copy packets which would slow down packet distribution, ACK generation, etc.. The buffer     belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket,     but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later     packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a     subsequent recvmsg(). Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to     using USHRT_MAX to indicate an invalid offset. Note also that I would generally prefer to replace the     buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and     frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks     like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to     have to allocate a new sk_buff. (CVE-2026-64026)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
333762	Photon OS 5.0: Linux PHSA-2026-5.0-92-0895	Nessus	PhotonOS Local Security Checks	Local	high
327921	Linux Distros Unpatched Vulnerability : CVE-2026-64026	Nessus	Misc.	Local	high
322944	Photon OS 5.0: Linux PHSA-2026-5.0-0895	Nessus	PhotonOS Local Security Checks	Local	high

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