net: gue: reject invalid REMCSUM offsets
In the Linux kernel, the following vulnerability has been resolved: net: gue: reject invalid REMCSUM offsets The REMCSUM option carries an absolute checksum start and checksum field offset. gue_remcsum() passes them to skb_remcsum_process(), whose partial path stores offset - start in the u16 skb->csum_offset variable. If offset is less than start, this underflows. A forwarded packet can retain CHECKSUM_PARTIAL and reach a NETIF_F_HW_CSUM driver which trusts the metadata, leading skb_copy_and_csum_dev() to write two bytes about 64 KiB beyond the destination buffer. Reject reversed tuples in validate_gue_flags(), after the existing length validation, so all GUE parsers enforce the ordering in one place.
CVE-2026-98621
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98621
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "4b9bc21b2396c396d88dd909caaf73d5be6ff593",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "43efb1f997e976f386aa89716f55870cd2cff9ad",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "1eeec0c51fd5598da44080ed96bbd9880021c28b",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "1d664be4ca49d1696e85239236f4988dfc4653c3",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "97f907203321eee2cc9132d5c9eb47698fb41d35",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "c20f755338ca234e523dfc943719f194dfc1f903",
"versionType": "git"
},
{
"status": "affected",
"version": "fe881ef11cf0220f118816181930494d484c4883",
"lessThan": "2566866fc30965d915d0b52b5c3323b362619f0e",
"versionType": "git"
}
],
"programFiles": [
"include/net/gue.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/gue.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98621
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38640 · Revision 1
- Added to Heist Feed
- Publisher date