CVE-2024-56638: linux
Vulnerability summary
CVE-2024-56638 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 24 · Related 24Timeline
- 27-12-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: incorrect percpu area handling under softirq Softirq can interrupt ongoing packet from process context that is walking over the percpu area that contains inner header offsets. Disable bh and perform three checks before restoring the percpu inner header offsets to validate that the percpu area is valid for this skbuff: 1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff has already been parsed before for inner header fetching to register. 2) Validate that the percpu area refers to this skbuff using the skbuff pointer as a cookie. If there is a cookie mismatch, then this skbuff needs to be parsed again. 3) Finally, validate if the percpu area refers to this tunnel type. Only after these three checks the percpu area is restored to a on-stack copy and bh is enabled again. After inner header fetching, the on-stack copy is stored back to the percpu area.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
0.00 pp
From 0.23% on 21-09-2026
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
Ubuntu105 products
- linux< 6.8.0-58.60
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1027.29
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 3a07327d10a09379315c844c63f27941f5081e0a, < 53c7314208c865086d78b4e88da53bc33da0b603 | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < da5cc778e7bf78fe525bc90ec2043f41415c31d9 | ≥ 3a07327d10a09379315c844c63f27941f5081e0a, < 7b1d83da254be3bf054965c8f3b1ad976f460ae5 | 6.2
- linux_kernel≥ 6.2, < 6.6.66 | ≥ 6.7, < 6.12.5 | 6.13:rc1
Debian1 product
- linux< 6.12.5-1
3 vendors · 108 products