CVE-2026-80988: Linux kernel · NTB: ntb_transport: Fail TX enqueue when the QP link is down
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch has been applied to the Linux kernel to fix this issue by correcting the return value of ntb_transport_tx_enqueue() to -ENOLINK when the QP link is down. Users should update to a kernel version that includes this fix. Since this is a kernel-level issue, applying the official patch or upgrading the kernel is the recommended remediation.
Description
In the Linux kernel, the following vulnerability has been resolved: NTB: ntb_transport: Fail TX enqueue when the QP link is down Commit f195a1a6fe41 ("ntb: Drop packets when qp link is down") meant to make ntb_transport_tx_enqueue() drop packets submitted while the QP link is down, but it only returns 0 without consuming the packet. Zero means success by this function's contract, so ntb_netdev reports NETDEV_TX_OK and forgets the skb: nothing queued it, nothing frees it, and it leaks, one skb for every transmit racing a link-down. Return -ENOLINK instead, restoring the contract that a non-zero return leaves the buffer owned by the caller. With the preceding patch, ntb_netdev frees the skb on non-retryable enqueue failures and returns NETDEV_TX_OK, so a packet racing with link-down is dropped without leaking or entering a busy retry loop.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80988 (opens in a new tab)
- git.kernel.org/stable/c/5eca0d899a3be661a7e2caaaa7467a6fa15d756c (opens in a new tab)
- git.kernel.org/stable/c/873ce713fef5dde0939220f04f3484ec86a16fba (opens in a new tab)
- git.kernel.org/stable/c/89177732fe1653bbfef10cf5d99bf20cf57762c2 (opens in a new tab)
- git.kernel.org/stable/c/894e136b432da75c0352c80299807a5c4b04f167 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80988 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80988 (opens in a new tab)
- git.kernel.org/linus/873ce713fef5dde0939220f04f3484ec86a16fba (opens in a new tab)