Answer in brief
CVE-2026-98374 records a Unknown severity vulnerability in tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack(). The current sources do not mark it as known exploited. The current feed maps 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.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <fad6d429651e748365e93ca54645accc212f0018 || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <c5b4da1f403a658c1c19766be2b426003ada419f || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <71d45049b0d631dfdbf3c65305f7fca676de023b || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <e3ea71cb1408a013ed4e8a757b815f1a919324bd || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <631aa4cb45099f09e9385dd786bd291c6270bfc4 || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <0f87720c7e4bcab07c24888b3cf12bfe857bb90e || >=c31b70c9968fe9c4194d1b5d06d07596a3b680de <fe99bbeee5c5dbd3abc30721a8079ced59649d97 | fad6d429651e748365e93ca54645accc212f0018, c5b4da1f403a658c1c19766be2b426003ada419f, 71d45049b0d631dfdbf3c65305f7fca676de023b, e3ea71cb1408a013ed4e8a757b815f1a919324bd, 631aa4cb45099f09e9385dd786bd291c6270bfc4, 0f87720c7e4bcab07c24888b3cf12bfe857bb90e, fe99bbeee5c5dbd3abc30721a8079ced59649d97 |
| Linux/Linuxgeneric | 5.11 | Not reported |
Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 7, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack() When tcp_send_synack() replaces the cloned SYN skb at the head of the retransmit queue with a copy, it frees the original with tcp_rtx_queue_unlink_and_free() and only repairs tp->highest_sack. tp->retransmit_skb_hint keeps pointing at the freed skbuff_fclone_cache object. The dangling hint is read in tcp_verify_retransmit_hint() and used as the root of the rbtree walk in tcp_xmit_retransmit_queue(). An unprivileged TFO client (sendmsg(MSG_FASTOPEN)) can arm the hint with an attacker-supplied ICMP fragmentation-needed message, after which a simultaneous open frees the armed SYN skb: BUG: KASAN: slab-use-after-free in tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) Read of size 4 at addr ffff88800604d928 by task swapper/1/0 Call Trace: tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) tcp_simple_retransmit (net/ipv4/tcp_input.c:3158) tcp_v4_err (net/ipv4/tcp_ipv4.c:587) Sync the hint to the copy.
Quoted source text, attributed separately from HOL analysis.