CVE-2026-31681
MEDIUMDescription
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_multiport: validate range encoding in checkentry
ports_match_v1() treats any non-zero pflags entry as the start of a
port range and unconditionally consumes the next ports[] element as
the range end.
The checkentry path currently validates protocol, flags and count, but
it does not validate the range encoding itself. As a result, malformed
rules can mark the last slot as a range start or place two range starts
back to back, leaving ports_match_v1() to step past the last valid
ports[] element while interpreting the rule.
Reject malformed multiport v1 rules in checkentry by validating that
each range start has a following element and that the following element
is not itself marked as another range start.
CVSS v3 vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected routers (1)
| Vendor | Model | Matched via | Affected versions | Fixed in | Patch Status |
|---|---|---|---|---|---|
| Ubiquiti | Ubiquiti EdgeRouter X | — |
— | — | Unpatched |