Answer in brief
CVE-2026-64543 records a High severity (CVSS 7.8) vulnerability in tipc: fix use-after-free of the discoverer in tipc_disc_rcv(). 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 7.8. 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 | >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <5e215bf1c47fdddf8203a0fe80a0ed594065f101 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <ec7d54d8cc1723921d671e3272b427c96366506f || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <b65289e1c3f352a9f92c6e19713ddd647e033253 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <1579342d71133da7f00daa02c75cebec7372097b | 5e215bf1c47fdddf8203a0fe80a0ed594065f101, ec7d54d8cc1723921d671e3272b427c96366506f, a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2, b65289e1c3f352a9f92c6e19713ddd647e033253, 1579342d71133da7f00daa02c75cebec7372097b |
| Linux/Linuxgeneric | 4.17 | Not reported |
| Linux/Linuxgeneric | >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <380413cdfd29fb9fa486c82889132b680c4983c5 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <f05b3f4c78370469286879c765f5a1dd39dbcd32 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <4da2ac7749411971e1b222b992da5a172ce45f98 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <5e215bf1c47fdddf8203a0fe80a0ed594065f101 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <ec7d54d8cc1723921d671e3272b427c96366506f || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <b65289e1c3f352a9f92c6e19713ddd647e033253 || >=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259 <1579342d71133da7f00daa02c75cebec7372097b | 380413cdfd29fb9fa486c82889132b680c4983c5, f05b3f4c78370469286879c765f5a1dd39dbcd32, 4da2ac7749411971e1b222b992da5a172ce45f98, 5e215bf1c47fdddf8203a0fe80a0ed594065f101, ec7d54d8cc1723921d671e3272b427c96366506f, a0c5fdeb5fa257f8c6d469af266bc087cb5de6a2, b65289e1c3f352a9f92c6e19713ddd647e033253, 1579342d71133da7f00daa02c75cebec7372097b |
Published upstream
Jul 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: tipc: fix use-after-free of the discoverer in tipc_disc_rcv() bearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(), but tipc_disc_rcv() still dereferences b->disc in RX softirq under rcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv). L2 bearers are safe thanks to the synchronize_net() in tipc_disable_l2_media(), but the UDP bearer defers that call to the cleanup_bearer() workqueue, so the discoverer is freed with no grace period: BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149) Read of size 8 at addr ffff88802348b728 by task poc_tipc/184 <IRQ> tipc_disc_rcv (net/tipc/discover.c:149) tipc_rcv (net/tipc/node.c:2126) tipc_udp_recv (net/tipc/udp_media.c:391) udp_rcv (net/ipv4/udp.c:2643) ip_local_deliver_finish (net/ipv4/ip_input.c:241) </IRQ> Freed by task 181: kfree (mm/slub.c:6565) bearer_disable (net/tipc/bearer.c:418) tipc_nl_bearer_disable (net/tipc/bearer.c:1001) The bearer is freed with kfree_rcu(); free the discoverer the same way. Add an rcu_head to struct tipc_discoverer and free it and its skb from an RCU callback. Because the RCU callback (tipc_disc_free_rcu) lives in module text, a call_rcu() that is still pending when the tipc module is unloaded would invoke a freed function. Add an rcu_barrier() to tipc_exit() after the bearer subsystem has been torn down, so all pending discoverer callbacks have run before the module text goes away. Reachable from an unprivileged user namespace: the TIPCv2 genl family is netnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC and CONFIG_TIPC_MEDIA_UDP.
Quoted source text, attributed separately from HOL analysis.