What’s Vulnerable › Vulnerabilities

CVE-2025-21903: mctp i3c: handle NULL header address

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-04-01 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: mctp i3c: handle NULL header address daddr can be NULL if there is no neighbour table entry present, in that case the tx packet should be dropped. saddr will usually be set by MCTP core, but check for NULL in case a packet is transmitted by a different protocol.

Affected products

• Linux kernel: from 6.7 before 6.12.19; from 6.13 before 6.13.7; 6.14-rc1, 6.14-rc2, 6.14-rc3, 6.14-rc4, 6.14-rc5 — fixed in 6.12.19, 6.13.7

How to fix

Upgrade to a fixed version: Linux kernel 6.12.19, 6.13.7. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/740bf9c9b715cc327d34b1e2d4ee79fcd4c47a56
• https://git.kernel.org/stable/c/cf7ee25e70c6edfac4553d6b671e8b19db1d9573
• https://git.kernel.org/stable/c/d8be54c35aee29d96d1350b1b6f153be4da37c07

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