CVE-2026-99152 (CVSS 7.5)

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the task named by a management response __iscsi_complete_pdu() fetches the task for five response types from one place and checks only that the index resolved: case ISCSI_OP_LOGOUT_RSP: case ISCSI_OP_LOGIN_RSP: case ISCSI_OP_TEXT_RSP: case ISCSI_OP_SCSI_TMFUNC_RSP: case ISCSI_OP_NOOP_IN: task = iscsi_itt_to_task(conn, hdr->itt); if (!task) return ISCSI_ERR_BAD_ITT; iscsi_itt_to_task() bounds the index against cmds_max and looks at nothing else, so a target can name any slot in the pool, including one that has never been used. task->conn is then NULL, and both iscsi_nop_out_rsp() and iscsi_complete_task() dereference it. One unsolicited NOP-In is enough; a Text Response carrying the same ITT crashes in iscsi_complete_task() instead. Require the task to be in flight and not a SCSI command, the way iscsi_itt_to_ctask() does for the command opcodes. [ 6.298634] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI [ 6.298642] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] [ 6.298652] CPU: 1 UID: 0 PID: 111 Comm: iscsistart Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy) [ 6.298654] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 6.298656] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160 [ 6.298691] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00 [ 6.298698] RSP: 0018:ffff88806c907be8 EFLAGS: 00010206 [ 6.298701] RAX: dffffc0000000000 RBX: ffff888006116800 RCX: 0000000000000020 [ 6.298702] RDX: 000000000000000c RSI: ffff88800525d578 RDI: 0000000000000060 [ 6.298703] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 6.298706] R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000 [ 6.298706] R13: 000000000000002e R14: ffff8880056eb440 R15: ffff888006116800 [ 6.298707] FS: 00007fc02d1c2740(0000) GS:ffff8880b29bc000(0000) knlGS:0000000000000000 [ 6.298710] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.298711] CR2: 000055fe3b56ddf8 CR3: 00000000053b9004 CR4: 0000000000770ef0 [ 6.298712] PKRU: 55555554 [ 6.298713] Call Trace: [ 6.298714] <IRQ> [ 6.298714] __iscsi_complete_pdu+0x13a8/0x22a0 [ 6.298758] iscsi_complete_pdu+0x54/0xa0 [ 6.298759] iscsi_tcp_hdr_recv_done+0x870/0x2c80 [ 6.298778] iscsi_tcp_recv_skb+0x31e/0xec0 [ 6.298800] iscsi_sw_tcp_recv+0x12f/0x390 [ 6.298804] __tcp_read_sock+0x1ab/0x810 [ 6.298812] iscsi_sw_tcp_data_ready+0x18b/0x510 [ 6.298814] tcp_rcv_established+0x1f56/0x3a00 [ 6.298842] tcp_v4_do_rcv+0x449/0x960 [ 6.298847] tcp_v4_rcv+0x2245/0x3bc0

Is your site exposed to CVE-2026-99152?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0052

Probability of exploitation

0.45%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/11bffcd9cb346732eab2914ef44fe777a3f0b585 https://git.kernel.org/stable/c/55a65ef61e2775aeb18fda63bd1959fa8b41f936 https://git.kernel.org/stable/c/5b56229cc152095fbe4e4ff537cb206c4aa41610 https://git.kernel.org/stable/c/77134cf996bab55683f0ceafb9e300d97ac046f8 https://git.kernel.org/stable/c/7a7a473aec51195778a54fdd71f20fda3047b8ef https://git.kernel.org/stable/c/bf4035656852a386fecb5d6217710a1bde536e76 https://git.kernel.org/stable/c/e96ae694c5038aae84142b64e41b56324b7af9a7 https://git.kernel.org/stable/c/f721487523d45941aed4b0ac8d829b0461a7d860

Frequently Asked Questions

What is CVE-2026-99152? +

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Validate the task named by a management response __iscsi_complete_pdu() fetches the task for five response types from one place and checks only that the index resolved: case ISCSI_OP_LOGOUT_RSP: case ISCSI_OP_LOGIN_RSP: case ISCSI_OP_TEXT_RSP: case ISCSI_OP_SCSI_TMFUNC_RSP: case ISCSI_OP_NOOP_IN: task = iscsi_itt_to_task(conn, hdr->itt); if (!task) return ISCSI_ERR_BAD_ITT; iscsi_itt_to_task() bounds the index against cmds_max and looks at nothing else, so a target can name any slot in the pool, including one that has never been used. task->conn is then NULL, and both iscsi_nop_out_rsp() and iscsi_complete_task() dereference it. One unsolicited NOP-In is enough; a Text Response carrying the same ITT crashes in iscsi_complete_task() instead. Require the task to be in flight and not a SCSI command, the way iscsi_itt_to_ctask() does for the command opcodes. [ 6.298634] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI [ 6.298642] KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067] [ 6.298652] CPU: 1 UID: 0 PID: 111 Comm: iscsistart Not tainted 7.2.0-rc5-ISCSI1-gf5098b6bae76 #1 PREEMPT(lazy) [ 6.298654] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 6.298656] RIP: 0010:iscsi_nop_out_rsp.constprop.0+0x46/0x160 [ 6.298691] Code: c1 ea 03 48 83 ec 08 80 3c 02 00 0f 85 f5 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 58 48 8d 7d 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 c0 00 00 00 48 8b 45 60 48 39 c3 74 50 48 b8 00 [ 6.298698] RSP: 0018:ffff88806c907be8 EFLAGS: 00010206 [ 6.298701] RAX: dffffc0000000000 RBX: ffff888006116800 RCX: 0000000000000020 [ 6.298702] RDX: 000000000000000c RSI: ffff88800525d578 RDI: 0000000000000060 [ 6.298703] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 6.298706] R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000000 [ 6.298706] R13: 000000000000002e R14: ffff8880056eb440 R15: ffff888006116800 [ 6.298707] FS: 00007fc02d1c2740(0000) GS:ffff8880b29bc000(0000) knlGS:0000000000000000 [ 6.298710] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6.298711] CR2: 000055fe3b56ddf8 CR3: 00000000053b9004 CR4: 0000000000770ef0 [ 6.298712] PKRU: 55555554 [ 6.298713] Call Trace: [ 6.298714] <IRQ> [ 6.298714] __iscsi_complete_pdu+0x13a8/0x22a0 [ 6.298758] iscsi_complete_pdu+0x54/0xa0 [ 6.298759] iscsi_tcp_hdr_recv_done+0x870/0x2c80 [ 6.298778] iscsi_tcp_recv_skb+0x31e/0xec0 [ 6.298800] iscsi_sw_tcp_recv+0x12f/0x390 [ 6.298804] __tcp_read_sock+0x1ab/0x810 [ 6.298812] iscsi_sw_tcp_data_ready+0x18b/0x510 [ 6.298814] tcp_rcv_established+0x1f56/0x3a00 [ 6.298842] tcp_v4_do_rcv+0x449/0x960 [ 6.298847] tcp_v4_rcv+0x2245/0x3bc0 It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-99152? +

CVE-2026-99152 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-99152? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-99152