CVE-2026-43371 — net: macb: Shuffle the tx ring before enabling tx
In the Linux kernel, the following vulnerability has been resolved: net: macb: Shuffle the tx ring before enabling tx Quanyang observed that when using an NFS rootfs on an AMD ZynqMp board, the rootfs may take an extended time to recover after a suspend. Upon investigation, it was determined that the issue originates from a problem in the macb driver. According to the Zynq UltraScale TRM [1], when transmit is disabled, the transmit buffer queue pointer resets to point to the address specified by the transmit buffer queue base address register. In the current implementation, the code merely resets `queue->tx_head` and `queue->tx_tail` to '0'. This approach presents several issues: - Packets already queued in the tx ring are silently lost, leading to memory leaks since the associated skbs cannot be released. - Concurrent write access to `queue->tx_head` and `queue->tx_tail` may occur from `macb_tx_poll()` or `macb_start_xmit()` when these values are reset to '0'. - The transmission may become stuck on a packet that has already been sent out, with its 'TX_USED' bit set, but has not yet been processed. However, due to the manipulation of 'queue->tx_head' and 'queue->tx_tail', `macb_tx_poll()` incorrectly assumes there are no packets to handle because `queue->tx_head == queue->tx_tail`. This issue is only resolved when a new packet is placed at this position. This is the root cause of the prolonged recovery time observed for the NFS root filesystem. To resolve this issue, shuffle the tx ring and tx skb array so that the first unsent packet is positioned at the start of the tx ring. Additionally, ensure that updates to `queue->tx_head` and `queue->tx_tail` are properly protected with the appropriate lock. [1] https://docs.amd.com/v/u/en-US/ug1085-zynq-ultrascale-trm
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 0.2% (30-day exploitation probability)+1
- Technical severity (medium)+3
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.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
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, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ d89b8b17057e16fad4564c71160e68ca549c1b42 and < c6783bfa31a59f34fe4feb1bdbf67791ef3fb0b7≥ ec4445ae9e58aed88561d3d1dfa849b039c7782e and < 0a47c3889fcd843c72aa57fa8c4d06f5801fced4≥ 6e704e89f16fd4a1145756210bc210f14f174f94 and < 88f974fe118cb4653f029929ecbca7cfe06132ae≥ 316d9fe71fb18bc9b1dba464fdb68dd201315eba and < 58f5d34f88e8f00910b692537f7b2efdb8c3705d≥ b3a7aa33ca7d46be513fccf832d3540acfe587d0 and < 403182e0771b250cfde0fe7e1081d095ceaf8230≥ bf9cf80cab81e39701861a42877a28295ade266f and < 881a0263d502e1a93ebc13a78254e9ad19520232≥ 6.1.165 and < 6.1.167≥ 6.6.128 and < 6.6.130 and 3 more≥ 6.12.75 and < 6.12.78≥ 6.18.16 and < 6.18.20≥ 6.19.6 and < 6.19.9 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.1.165 and < 6.1.167≥ 6.6.128 and < 6.6.130≥ 6.12.75 and < 6.12.78≥ 6.18.16 and < 6.18.20≥ 6.19.6 and < 6.19.9 | Vulnerable | NIST National Vulnerability Database |
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 |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-401 · Missing Release of Memory after Effective Lifetime
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.16%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- 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/c6783bfa31a59f34fe4feb1bdbf67791ef3fb0b7
- git.kernel.org/stable/c/0a47c3889fcd843c72aa57fa8c4d06f5801fced4
- git.kernel.org/stable/c/88f974fe118cb4653f029929ecbca7cfe06132ae
- git.kernel.org/stable/c/58f5d34f88e8f00910b692537f7b2efdb8c3705d
- git.kernel.org/stable/c/403182e0771b250cfde0fe7e1081d095ceaf8230
- git.kernel.org/stable/c/881a0263d502e1a93ebc13a78254e9ad19520232
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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 CISA SSVC assessment.
- 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-2026-43371 is "net: macb: Shuffle the tx ring before enabling tx", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.16% 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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