CVE-2026-89783 is a vulnerability in Linux Kernel
Published on September 16, 2026
xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full
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]'
Products Associated with CVE-2026-89783
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Affected Versions
Linux:- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 91fc387f63c00ddfb5221127a17bac97549a8343 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 68e8737fe8e72f085c608cff322b3d2de8340af1 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 8fe2c53fb81f5ad5be43af2ad09583f7c78b4b77 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below bdcda866c89f9a8b1acdabf02d26cde9fbe501d8 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 48996649222e95008cdb98cd58579e3fc8e5ee06 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 0f679e0523ddfff3fb554336ceb874b0e51e9cd3 is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 5f35a29a5eed3d80befd32050843ac88dea3d61a is affected.
- Version 9473e1f631de339c50bde1e3bd09e1045fe90fd5 and below 5d9e3bf34fec9a5d237e4b7cef4a707bc2e091bc is affected.
- Version 2.6.25 is affected.
- Before 2.6.25 is unaffected.
- Version 5.10.270, <= 5.10.* is unaffected.
- Version 5.15.221, <= 5.15.* is unaffected.
- Version 6.1.188, <= 6.1.* is unaffected.
- Version 6.6.157, <= 6.6.* is unaffected.
- Version 6.12.110, <= 6.12.* is unaffected.
- Version 6.18.52, <= 6.18.* is unaffected.
- Version 7.2.6, <= 7.2.* is unaffected.
- Version 7.3-rc1, <= * is unaffected.