CVE-2025-21903: linux
Vulnerability summary
CVE-2025-21903 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 18 · Related 18Timeline
- 01-04-2025PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
0.00 pp
From 0.20% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu110 products
- linux< 6.8.0-84.84
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1039.41
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ c8755b29b58ec65be17bcb8c40763d2dcb1f1db5, < d8be54c35aee29d96d1350b1b6f153be4da37c07 | ≥ c8755b29b58ec65be17bcb8c40763d2dcb1f1db5, < 740bf9c9b715cc327d34b1e2d4ee79fcd4c47a56 | ≥ c8755b29b58ec65be17bcb8c40763d2dcb1f1db5, < cf7ee25e70c6edfac4553d6b671e8b19db1d9573 | 6.7
- linux_kernel≥ 6.7, < 6.12.19 | ≥ 6.13, < 6.13.7 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4 | 6.14:rc5
Debian1 product
- linux< 6.12.19-1
3 vendors · 113 products
