In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_tunnel: fix geneve_opt type confusion addition
When handling multiple NFTA_TUNNEL_KEY_OPTS_GENEVE attributes, the
parsing logic should place every geneve_opt structure one by one
compactly. Hence, when deciding the next geneve_opt position, the
pointer addition should be in units of char *.
However, the current implementation erroneously does type conversion
before the addition, which will lead to heap out-of-bounds write.
[ 6.989857] ==================================================================
[ 6.990293] BUG: KASAN: slab-out-of-bounds in nft_tunnel_obj_init+0x977/0xa70
[ 6.990725] Write of size 124 at addr ffff888005f18974 by task poc/178
[ 6.991162]
[ 6.991259] CPU: 0 PID: 178 Comm: poc-oob-write Not tainted 6.1.132 #1
[ 6.991655] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[ 6.992281] Call Trace:
[ 6.992423]
[ 6.992586] dump_stack_lvl+0x44/0x5c
[ 6.992801] print_report+0x184/0x4be
[ 6.993790] kasan_report+0xc5/0x100
[ 6.994252] kasan_check_range+0xf3/0x1a0
[ 6.994486] memcpy+0x38/0x60
[ 6.994692] nft_tunnel_obj_init+0x977/0xa70
[ 6.995677] nft_obj_init+0x10c/0x1b0
[ 6.995891] nf_tables_newobj+0x585/0x950
[ 6.996922] nfnetlink_rcv_batch+0xdf9/0x1020
[ 6.998997] nfnetlink_rcv+0x1df/0x220
[ 6.999537] netlink_unicast+0x395/0x530
[ 7.000771] netlink_sendmsg+0x3d0/0x6d0
[ 7.001462] __sock_sendmsg+0x99/0xa0
[ 7.001707] ____sys_sendmsg+0x409/0x450
[ 7.002391] ___sys_sendmsg+0xfd/0x170
[ 7.003145] __sys_sendmsg+0xea/0x170
[ 7.004359] do_syscall_64+0x5e/0x90
[ 7.005817] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 7.006127] RIP: 0033:0x7ec756d4e407
[ 7.006339] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf
[ 7.007364] RSP: 002b:00007ffed5d46760 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 7.007827] RAX: ffffffffffffffda RBX: 00007ec756cc4740 RCX: 00007ec756d4e407
[ 7.008223] RDX: 0000000000000000 RSI: 00007ffed5d467f0 RDI: 0000000000000003
[ 7.008620] RBP: 00007ffed5d468a0 R08: 0000000000000000 R09: 0000000000000000
[ 7.009039] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[ 7.009429] R13: 00007ffed5d478b0 R14: 00007ec756ee5000 R15: 00005cbd4e655cb8
Fix this bug with correct pointer addition and conversion in parse
and dump code.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it