CVE-2026-23438: Linux kernel · net: mvpp2: guard flow control update with global_tx_fc in buffer switching
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Apr 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 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther 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 is available and should be applied to affected Linux kernel versions to add the missing guard check in mvpp2_bm_switch_buffers(). The fix prevents kernel crashes by ensuring hardware registers are only accessed when the CM3 SRAM resource is present. Users should update to patched kernel versions as per the vendor advisory.
Description
A vulnerability in the Linux kernel's mvpp2 network driver could cause a kernel crash due to a NULL pointer dereference when switching buffer pools without proper hardware flow control checks. This occurs when the CM3 SRAM resource is missing from the device tree, leading to an unguarded access of a NULL pointer during operations such as MTU changes crossing the jumbo frame threshold. The issue has been fixed by adding the missing guard check consistent with other driver code.
References
- ubuntu.com/security/CVE-2026-23438 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23438 (opens in a new tab)
- git.kernel.org/linus/8a63baadf08453f66eb582fdb6dd234f72024723 (opens in a new tab)
- git.kernel.org/stable/c/7bd20f4b3ef3044dc55acd5b8ef748a70d29d03f (opens in a new tab)
- git.kernel.org/stable/c/7df2b50cae1a76cbb90b294f3edb61e3e10bf2e9 (opens in a new tab)
- git.kernel.org/stable/c/8a63baadf08453f66eb582fdb6dd234f72024723 (opens in a new tab)
- git.kernel.org/stable/c/8baced53a35fc9710f80d6ca016a2c418dc3231f (opens in a new tab)
- git.kernel.org/stable/c/da089f74a993f846685067b14158cb41b879ff29 (opens in a new tab)
- git.kernel.org/stable/c/ff0c54f088f7ab91dbbf47cf8244460f99122750 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)