net: ipconfig: bound DHCP option construction
In the Linux kernel, the following vulnerability has been resolved: net: ipconfig: bound DHCP option construction ic_dhcp_init_options() appends the hostname (option 12), vendor-class (option 60) and client-ID (option 61) options into the fixed 312-byte bootp_pkt.exten[] buffer. Only the client-ID branch checked the remaining space; the hostname and vendor-class writes were unbounded. A 64-byte hostname together with the maximum 252-byte dhcpclass= identifier needs 18 + (2 + 64) + (2 + 252) = 338 of the 312 available bytes even before the terminating END marker, so the vendor-class memcpy runs past the end of exten[]. With CONFIG_FORTIFY_SOURCE this is reported as a field-spanning write and, when the kernel is booted with panic_on_warn=1, aborts boot with a panic. Route the optional options through a common helper that makes sure the option, its 2-byte header and the END marker all fit and drops an option that would not. Configurations with short options keep sending exactly the same bytes as before.
CVE-2026-98493
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-2026-98493
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": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
"lessThan": "38a6a118260ebfc82d0c653194d616bdfbd236ac",
"versionType": "git"
},
{
"status": "affected",
"version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
"lessThan": "abcba6f080c63e403037ecdffde43170d242376a",
"versionType": "git"
},
{
"status": "affected",
"version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
"lessThan": "24e79508b237dd2a69bc6fb6ac5cf7f126178307",
"versionType": "git"
},
{
"status": "affected",
"version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
"lessThan": "cbaad2922bd5d4d303055ae9afecc8999e6b40c9",
"versionType": "git"
},
{
"status": "affected",
"version": "130c0f47fdf9c533deb1136cad5136f6cb7020f0",
"lessThan": "e47a1958e12abc3a17b5231a4f21c8f1bf662e08",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/ipconfig.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.36"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.36",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"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": [
"net/ipv4/ipconfig.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98493
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48885 · Revision 1
- Added to Heist Feed
- Publisher date