Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.16% for the current model date.
BlackTreeCVE IntelligenceLinux · Linux
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 9 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-azure-6.11 | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-gcp-6.11 | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-hwe-6.11 | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-intel | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-lowlatency-hwe-6.11 | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-oem-6.11 | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-riscv | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by productIn the Linux kernel, the following vulnerability has been resolved: xsk: check IFF_UP earlier in Tx path Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll().
In the Linux kernel, the following vulnerability has been resolved: xsk: check IFF_UP earlier in Tx path Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll().
The product dereferences a pointer that it expects to be valid but is NULL.
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
In the Linux kernel, the following vulnerability has been resolved: xsk: check IFF_UP earlier in Tx path Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll().
The product dereferences a pointer that it expects to be valid but is NULL.
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 15 Sept 2025 · Last source change 23 May 2026, 15:28 UTC · CWE-476 · NULL Pointer Dereference
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.