Answer in brief
CVE-2026-98549 records a Critical severity (CVSS 9.1) vulnerability in tcp: prevent collapsing skbs across boundary in rtx queue. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=e8f69799810c32dd40c6724d829eccc70baad07f <1ae7aee395245874d797890380d9192bd858fb7e || >=e8f69799810c32dd40c6724d829eccc70baad07f <7ba87509c54cd519e7ed362e0c85e8431f066a18 || >=e8f69799810c32dd40c6724d829eccc70baad07f <08e835f5ec6e261c79d8c39f8618b3af29e3b0da || >=e8f69799810c32dd40c6724d829eccc70baad07f <fc6d80eb504458d6416b75a94188b268c95c6533 | 1ae7aee395245874d797890380d9192bd858fb7e, 7ba87509c54cd519e7ed362e0c85e8431f066a18, 08e835f5ec6e261c79d8c39f8618b3af29e3b0da, fc6d80eb504458d6416b75a94188b268c95c6533 |
| Linux/Linuxgeneric | 4.18 | Not reported |
| Linux/Linuxgeneric | >=e8f69799810c32dd40c6724d829eccc70baad07f <9e2a2f98e8c0197108c6d97a1fa43bfd89071c30 || >=e8f69799810c32dd40c6724d829eccc70baad07f <1ae7aee395245874d797890380d9192bd858fb7e || >=e8f69799810c32dd40c6724d829eccc70baad07f <7ba87509c54cd519e7ed362e0c85e8431f066a18 || >=e8f69799810c32dd40c6724d829eccc70baad07f <08e835f5ec6e261c79d8c39f8618b3af29e3b0da || >=e8f69799810c32dd40c6724d829eccc70baad07f <fc6d80eb504458d6416b75a94188b268c95c6533 | 9e2a2f98e8c0197108c6d97a1fa43bfd89071c30, 1ae7aee395245874d797890380d9192bd858fb7e, 7ba87509c54cd519e7ed362e0c85e8431f066a18, 08e835f5ec6e261c79d8c39f8618b3af29e3b0da, fc6d80eb504458d6416b75a94188b268c95c6533 |
Published upstream
Oct 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 18, 2026
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.
Quoted source text, attributed separately from HOL analysis.