Answer in brief
CVE-2025-37921 records a High severity (CVSS 7.8) vulnerability in vxlan: vnifilter: Fix unlocked deletion of default FDB entry. 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.
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). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <2d4a121296aa3940d2df9906f955c2b6b4e38bc3 || >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed || >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <5cb9e07f84e527974b12e82e2549fa6c0cc6eef0 || >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <470206205588559e60035fceb5f256640cb45f99 || >=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <087a9eb9e5978e3ba362e1163691e41097e8ca20 | 2d4a121296aa3940d2df9906f955c2b6b4e38bc3, 3576e9a80b6c4381b01ce0cbaa07f5e92d4492ed, 5cb9e07f84e527974b12e82e2549fa6c0cc6eef0, 470206205588559e60035fceb5f256640cb45f99, 087a9eb9e5978e3ba362e1163691e41097e8ca20 |
| Linux/Linuxgeneric | 5.18 | Not reported |
Published upstream
May 20, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 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: vxlan: vnifilter: Fix unlocked deletion of default FDB entry When a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB entry associated with the default remote (assuming one was configured) is deleted without holding the hash lock. This is wrong and will result in a warning [1] being generated by the lockdep annotation that was added by commit ebe642067455 ("vxlan: Create wrappers for FDB lookup"). Reproducer: # ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1 # bridge vni add vni 10010 remote 198.51.100.1 dev vx0 # bridge vni del vni 10010 dev vx0 Fix by acquiring the hash lock before the deletion and releasing it afterwards. Blame the original commit that introduced the issue rather than the one that exposed it. [1] WARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0 [...] RIP: 0010:vxlan_find_mac+0x17f/0x1a0 [...] Call Trace: <TASK> __vxlan_fdb_delete+0xbe/0x560 vxlan_vni_delete_group+0x2ba/0x940 vxlan_vni_del.isra.0+0x15f/0x580 vxlan_process_vni_filter+0x38b/0x7b0 vxlan_vnifilter_process+0x3bb/0x510 rtnetlink_rcv_msg+0x2f7/0xb70 netlink_rcv_skb+0x131/0x360 netlink_unicast+0x426/0x710 netlink_sendmsg+0x75a/0xc20 __sock_sendmsg+0xc1/0x150 ____sys_sendmsg+0x5aa/0x7b0 ___sys_sendmsg+0xfc/0x180 __sys_sendmsg+0x121/0x1b0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x4b/0x53
Quoted source text, attributed separately from HOL analysis.