In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix mlx5_poll_one() cur_qp update flow
When cur_qp isn't NULL, in order to avoid fetching the QP from
the radix tree again we check if the next cqe QP is identical to
the one we already have.
The bug however is that we are checking if the QP is identical by
checking the QP number inside the CQE against the QP number inside the
mlx5_ib_qp, but that's wrong since the QP number from the CQE is from
FW so it should be matched against mlx5_core_qp which is our FW QP
number.
Otherwise we could use the wrong QP when handling a CQE which could
cause the kernel trace below.
This issue is mainly noticeable over QPs 0 & 1, since for now they are
the only QPs in our driver whereas the QP number inside mlx5_ib_qp
doesn't match the QP number inside mlx5_core_qp.
BUG: kernel NULL pointer dereference, address: 0000000000000012
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP
CPU: 0 UID: 0 PID: 7927 Comm: kworker/u62:1 Not tainted 6.14.0-rc3+ #189
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core]
RIP: 0010:mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib]
Code: 03 00 00 8d 58 ff 21 cb 66 39 d3 74 39 48 c7 c7 3c 89 6e a0 0f b7 db e8 b7 d2 b3 e0 49 8b 86 60 03 00 00 48 c7 c7 4a 89 6e a0 <0f> b7 5c 98 02 e8 9f d2 b3 e0 41 0f b7 86 78 03 00 00 83 e8 01 21
RSP: 0018:ffff88810511bd60 EFLAGS: 00010046
RAX: 0000000000000010 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88885fa1b3c0 RDI: ffffffffa06e894a
RBP: 00000000000000b0 R08: 0000000000000000 R09: ffff88810511bc10
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88810d593000
R13: ffff88810e579108 R14: ffff888105146000 R15: 00000000000000b0
FS: 0000000000000000(0000) GS:ffff88885fa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000012 CR3: 00000001077e6001 CR4: 0000000000370eb0
Call Trace:
? __die+0x20/0x60
? page_fault_oops+0x150/0x3e0
? exc_page_fault+0x74/0x130
? asm_exc_page_fault+0x22/0x30
? mlx5_ib_poll_cq+0x4c7/0xd90 [mlx5_ib]
__ib_process_cq+0x5a/0x150 [ib_core]
ib_cq_poll_work+0x31/0x90 [ib_core]
process_one_work+0x169/0x320
worker_thread+0x288/0x3a0
? work_busy+0xb0/0xb0
kthread+0xd7/0x1f0
? kthreads_online_cpu+0x130/0x130
? kthreads_online_cpu+0x130/0x130
ret_from_fork+0x2d/0x50
? kthreads_online_cpu+0x130/0x130
ret_from_fork_asm+0x11/0x20
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it