CVE-2026-89783
Received
Received - Intake
Buffer Overflow in Linux Kernel xfrm6_input_addr
Vulnerability report for CVE-2026-89783, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-16
Last updated on: 2026-09-16
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full
The depth check in xfrm6_input_addr() is off by one:
if (1 + sp->len == XFRM_MAX_DEPTH)
goto drop;
...
sp->xvec[sp->len++] = x;
xfrm_input() can leave sp->len == XFRM_MAX_DEPTH, and the transport-mode
receive path re-enters IPv6 input via xfrm_trans_reinject() with that
secpath preserved. If the inner packet carries a destination-options HAO
option or a type-2 routing header, xfrm6_input_addr() is called with
sp->len == XFRM_MAX_DEPTH; the check (1 + 6 == 6) is false, so
sp->xvec[sp->len++] writes one slot past the 6-element xvec[]. The write
stays within the sec_path allocation (invisible to KASAN); UBSAN_BOUNDS
flags it and panics under panic_on_warn.
Use "sp->len >= XFRM_MAX_DEPTH", matching xfrm_input(). This also
restores one chain level the old check rejected at sp->len == 5.
UBSAN: array-index-out-of-bounds in net/ipv6/xfrm6_input.c:309:10
index 6 is out of range for type 'xfrm_state *[6]'
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
