CVE-2026-98549
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk33th percentile - higher than 33% of all known CVEs
Summary
A vulnerability in the Linux kernel TCP stack related to collapsing skbs in the retransmit queue has been fixed. The tcp_write_collapse_fence() function was a no-op when the write queue was empty, allowing skbs queued after a device encryption switch to be merged with earlier skbs. As a result, data could be retransmitted in cleartext (psp) or the connection could stall (tls device offload).
Risk Assessment
An organization may experience cleartext data leakage during retransmission when using psp device encryption, or persistent connection stalls for TLS device offload on mlx5, nfp, and funeth drivers.
Recommendation
Update the Linux kernel to a version containing the fix as soon as possible. Until then, avoid configurations using psp device encryption and TLS device offload on the affected drivers.
Other vulnerabilities in Linux kernel
See all- CVE-2026-58942High
In do_fault_around of memory.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58847Unknown
In kvm_vfio_pviommu_attach of vfio.c, there is a possible double free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
- CVE-2026-58829High
In fuse_backing_mmap of backing.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58828High
In multiple functions of base.c, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58827High
In multiple functions of dma-buf.c, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58826High
In ksys_unshare of fork.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58825High
In multiple functions of fork.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-99242Unknown
In the Linux kernel, a race between fallocate and mmap reads in NTFS was fixed. Fallocate only took invalidate_lock for punch hole, collapse range and insert range operations, and during standard allocation new clusters were mapped before being zeroed, allowing concurrent mmap page faults to read uninitialized disk data.
- CVE-2026-99241Unknown
In the Linux kernel, a missing lock in ntfs_filemap_page_mkwrite() was fixed; it called iomap_page_mkwrite() without holding mapping->invalidate_lock. A concurrent truncate or fallocate could be invalidating pagecache and rewriting the runlist while the write fault mapped blocks and dirtied the folio.
- CVE-2026-99240Unknown
In the Linux kernel, the DAMON subsystem (mm/damon/core) has a division-by-zero bug when a DAMOS quota goal has a target_value of zero. The fix moves handling of this corner case to the core layer by adding validation in damos_commit_quota_goal(), which now returns an error for zero target values.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: tcp: prevent collapsing skbs across boundary in rtx queue tcp_write_collapse_fence() sets TCP_SKB_CB(skb)->eor = 1 on tcp_write_queue_tail(sk) to prevent skbs queued after a switch to device encryption from being collapsed into earlier skbs. The fence is a no-op if all earlier data has already been transmitted when the switch happens: sk->sk_write_queue is empty. The not yet acknowledged earlier skbs wait in sk->tcp_rtx_queue with eor 0. On a subsequent retransmit or SACK shift, tcp_retrans_try_collapse() or tcp_shift_skb_data() can then merge an skb queued after the switch into one queued before it. Both users of the fence are affected: - psp: devices only encrypt skbs with skb->decrypted set. The merged skb keeps decrypted = 0 from the earlier skb, so merged data sent after psp_sock_assoc_set_tx() is retransmitted in cleartext. - tls device offload: the merged skb straddles the start marker set in tls_set_device_offload(). The software fallback (fill_sg_in() returns -EINVAL) and the mlx5, nfp and funeth drivers cannot handle such an skb and drop it. Every retransmit rebuilds the same skb, so the connection stalls. Fix this in two places, for defense in depth: 1. Fall back to tcp_rtx_queue_tail(sk) in tcp_write_collapse_fence() when tcp_write_queue_tail(sk) is NULL. 2. Check !skb_cmp_decrypted(to, from) in tcp_skb_can_collapse(), as tcp_skb_can_collapse_rx() does on receive. skb_shift(), which both collapse paths call, already has a DEBUG_NET_WARN_ON_ONCE() for this condition.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS