CVE-2023-53986 — mips: bmips: BCM6358: disable RAC flush for TP1
In the Linux kernel, the following vulnerability has been resolved: mips: bmips: BCM6358: disable RAC flush for TP1 RAC flush causes kernel panics on BCM6358 with EHCI/OHCI when booting from TP1: [ 3.881739] usb 1-1: new high-speed USB device number 2 using ehci-platform [ 3.895011] Reserved instruction in kernel code[#1]: [ 3.900113] CPU: 0 PID: 1 Comm: init Not tainted 5.10.16 #0 [ 3.905829] $ 0 : 00000000 10008700 00000000 77d94060 [ 3.911238] $ 4 : 7fd1f088 00000000 81431cac 81431ca0 [ 3.916641] $ 8 : 00000000 ffffefff 8075cd34 00000000 [ 3.922043] $12 : 806f8d40 f3e812b7 00000000 000d9aaa [ 3.927446] $16 : 7fd1f068 7fd1f080 7ff559b8 81428470 [ 3.932848] $20 : 00000000 00000000 55590000 77d70000 [ 3.938251] $24 : 00000018 00000010 [ 3.943655] $28 : 81430000 81431e60 81431f28 800157fc [ 3.949058] Hi : 00000000 [ 3.952013] Lo : 00000000 [ 3.955019] epc : 80015808 setup_sigcontext+0x54/0x24c [ 3.960464] ra : 800157fc setup_sigcontext+0x48/0x24c [ 3.965913] Status: 10008703 KERNEL EXL IE [ 3.970216] Cause : 00800028 (ExcCode 0a) [ 3.974340] PrId : 0002a010 (Broadcom BMIPS4350) [ 3.979170] Modules linked in: ohci_platform ohci_hcd fsl_mph_dr_of ehci_platform ehci_fsl ehci_hcd gpio_button_hotplug usbcore nls_base usb_common [ 3.992907] Process init (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=77e22ec8) [ 4.000776] Stack : 81431ef4 7fd1f080 81431f28 81428470 7fd1f068 81431edc 7ff559b8 81428470 [ 4.009467] 81431f28 7fd1f080 55590000 77d70000 77d5498c 80015c70 806f0000 8063ae74 [ 4.018149] 08100002 81431f28 0000000a 08100002 81431f28 0000000a 77d6b418 00000003 [ 4.026831] ffffffff 80016414 80080734 81431ecc 81431ecc 00000001 00000000 04000000 [ 4.035512] 77d54874 00000000 00000000 00000000 00000000 00000012 00000002 00000000 [ 4.044196] ... [ 4.046706] Call Trace: [ 4.049238] [<80015808>] setup_sigcontext+0x54/0x24c [ 4.054356] [<80015c70>] setup_frame+0xdc/0x124 [ 4.059015] [<80016414>] do_notify_resume+0x1dc/0x288 [ 4.064207] [<80011b50>] work_notifysig+0x10/0x18 [ 4.069036] [ 4.070538] Code: 8fc300b4 00001025 26240008 <ac820000> ac830004 3c048063 0c0228aa 24846a00 26240010 [ 4.080686] [ 4.082517] ---[ end trace 22a8edb41f5f983b ]--- [ 4.087374] Kernel panic - not syncing: Fatal exception [ 4.092753] Rebooting in 1 seconds.. Because the bootloader (CFE) is not initializing the Read-ahead cache properly on the second thread (TP1). Since the RAC was not initialized properly, we should avoid flushing it at the risk of corrupting the instruction stream as seen in the trace above.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+5
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < d65de5ee8b72868fbbbd39ca73017d0e526fa13a≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < 47a449ec09b4479b89dcc6b27ec3829fc82ffafb≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < 65b723644294f1d79770704162c0e8d1f700b6f1≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < 2cdbcff99f15db86a10672fb220379a1ae46ccae≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < 288c96aa5b5526cd4a946e84ef85e165857693b5≥ d59098a0e9cb3c7767090e935c909b37a30629ab and < ab327f8acdf8d06601fbf058859a539a9422afffversion 4.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.6 | CVSS 3.1 | High | 3.9 | 4.7 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 8.6 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.44%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- CVSS changed · 8.6
- Source status changed · → Deferred
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
6 on the record
- git.kernel.org/stable/c/47a449ec09b4479b89dcc6b27ec3829fc82ffafb
- git.kernel.org/stable/c/65b723644294f1d79770704162c0e8d1f700b6f1
- git.kernel.org/stable/c/d65de5ee8b72868fbbbd39ca73017d0e526fa13a
- git.kernel.org/stable/c/288c96aa5b5526cd4a946e84ef85e165857693b5
- git.kernel.org/stable/c/2cdbcff99f15db86a10672fb220379a1ae46ccae
- git.kernel.org/stable/c/ab327f8acdf8d06601fbf058859a539a9422afff
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-53986 is "mips: bmips: BCM6358: disable RAC flush for TP1", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.6 describes technical severity. EPSS 0.44% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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