CVE-2026-53366: ipv4: account for fraggap on the paged allocation path
Vulnerability summary
CVE-2026-53366 is a high (CVSS 7.8) Incorrect Calculation of Buffer Size vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.5% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 150 · Related 148Showing 100 of 151.
Timeline
- 16-07-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: account for fraggap on the paged allocation path In __ip_append_data(), when the paged-allocation branch is taken, alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap, but the fraggap bytes carried over from the previous skb are copied into the new skb's linear area at offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic.
CVSS metrics
5 scores · 5 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
- OSV · ChainguardEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.17% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu142 products
- linuxAll versions (No fix recorded) | < 6.8.0-147.147 | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 6.8.0-1067.70 | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Chainguard2 products
- linux-gcp-6.18< 6.18.39-r0
- linux-gcp-6.18-bootc< 6.18.39-r0
Linux2 products
- linux≥ 8eb77cc73977d88787b37c92831b1c242e035396, < 5c6375bced6147ec2e460ee3b653f4860d5ecdc2 | ≥ 8eb77cc73977d88787b37c92831b1c242e035396, < ce494707a9c07f27c219ca67f3e138061f53d9b3 | ≥ 8eb77cc73977d88787b37c92831b1c242e035396, < a9c24eda24bd15f432e37824e6fc440977cb241c | ≥ 8eb77cc73977d88787b37c92831b1c242e035396, < 77798d7be6ef71e72fb6fc8a2901bf74ebc9706f | ≥ 8eb77cc73977d88787b37c92831b1c242e035396, < c04d9ece23deb9e26c19f9ca215e98b3295aa1bb | ≥ 8eb77cc73977d88787b37c92831b1c242e035396, < eca856950f7cb1a221e02b99d758409f2c5cec42 | 6.0
- linux_kernel≥ 6.0, < 6.6.144 | ≥ 6.7, < 6.12.95 | ≥ 6.13, < 6.18.38 | ≥ 6.19, < 7.1.3
Suse2 products
- kernel-livepatch-SLE15-SP7_Update_18&distro=SUSE Linux Enterprise Live Patching 15 SP7< 2-150700.2.1
- kernel-livepatch-SLE15-SP7-RT_Update_17&distro=SUSE Linux Enterprise Live Patching 15 SP7< 2-150700.2.1
Debian1 product
- linux< 6.1.177-1 | < 6.12.95-1 | < 7.1.3-1
5 vendors · 149 products
