cbcvebase.
CVE-2026-46133
published 2026-05-28

CVE-2026-46133: In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject unknown opcodes before ICRC processing Even after applying commit…

PriorityP344high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.57%
44.1th percentile
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject unknown opcodes before ICRC processing Even after applying commit 7244491dab34 ("RDMA/rxe: Validate pad and ICRC before payload_size() in rxe_rcv"), a single unauthenticated UDP packet can still trigger panic. That patch handled payload_size() underflow only for valid opcodes with short packets, not for packets carrying an unknown opcode. The unknown-opcode OOB read described below predates that commit and reaches back to the initial Soft RoCE driver. The check added there reads pkt->paylen opcode].length. The rxe_opcode[] array has 256 entries but is only populated for defined IB opcodes; any other entry (for example opcode 0xff) is zero-initialized, so length == 0 and the check degenerates to pkt->paylen paylen enough. rxe_icrc_hdr() then computes rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES which underflows when length == 0 and passes a huge value to rxe_crc32(), causing an out-of-bounds read of the skb payload. Reproduced on v7.0-rc7 with that fix applied, QEMU/KVM with CONFIG_RDMA_RXE=y and CONFIG_KASAN=y, after rdma link add rxe0 type rxe netdev eth0 A single 48-byte UDP packet to port 4791 with BTH opcode=0xff and QPN=IB_MULTICAST_QPN triggers: BUG: KASAN: slab-out-of-bounds in crc32_le+0x115/0x170 Read of size 1 at addr ... The buggy address is located 0 bytes to the right of allocated 704-byte region Call Trace: crc32_le+0x115/0x170 rxe_icrc_hdr.isra.0+0x226/0x300 rxe_icrc_check+0x13f/0x3a0 rxe_rcv+0x6e1/0x16e0 rxe_udp_encap_recv+0x20a/0x320 udp_queue_rcv_one_skb+0x7ed/0x12c0 Subsequent packets with the same shape fault on unmapped memory and panic the kernel. The trigger requires only module load and "rdma link add"; no QP, no connection, and no authentication. Fix this by rejecting packets whose opcode has no rxe_opcode[] entry, detected via the zero mask or zero length, before any length arithmetic runs.

Affected

59 ranges· showing 25
VendorProductVersion rangeFixed in
linuxlinux
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 318787fa7193bd79691f2ebce4e80cb6abd0faef318787fa7193bd79691f2ebce4e80cb6abd0faef
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 6a79b1ea0fcb2c998fda6a793050f66146e9cc426a79b1ea0fcb2c998fda6a793050f66146e9cc42
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 599cfdf44c1701c581cd4a21f1e1e03f8dc3840b599cfdf44c1701c581cd4a21f1e1e03f8dc3840b
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < e3dc3a2fb05f4ed49c7f20594c4c52350d032189e3dc3a2fb05f4ed49c7f20594c4c52350d032189
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < f8ee926431a7bbec2b10c1290664af2cb290b983f8ee926431a7bbec2b10c1290664af2cb290b983
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 006a3a5f75345c6a0dbf13fd3ee01406e93b6733006a3a5f75345c6a0dbf13fd3ee01406e93b6733
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 6fa18025e5782afff91415fd5217b39c1e4837d76fa18025e5782afff91415fd5217b39c1e4837d7
linuxlinux>= 8700e3e7c4857d28ebaa824509934556da0b3e76 < 4c6f86d85d03cdb33addce86aa69aa795ca6c47a4c6f86d85d03cdb33addce86aa69aa795ca6c47a
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 4.8 < 5.10.2585.10.258
linuxlinux_kernel>= 5.11 < 5.15.2095.15.209
linuxlinux_kernel>= 5.16 < 6.1.1756.1.175
linuxlinux_kernel>= 6.13 < 6.18.306.18.30
linuxlinux_kernel>= 6.19 < 7.0.77.0.7
linuxlinux_kernel>= 6.2 < 6.6.1406.6.140
linuxlinux_kernel>= 6.7 < 6.12.886.12.88
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-5.15
ubuntulinux-aws-fips
ubuntulinux-azure
ubuntulinux-azure-5.15

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_ubuntu7.1HIGH
vendor_redhat7.0MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.