CVE-2026-45845
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
In the Linux kernel, a NULL pointer dereference vulnerability was found in the TAPRIO network scheduler during class dump. Deleting a child qdisc via RTM_DELQDISC stores NULL in the q->qdiscs[] array, and a subsequent class dump operation (RTM_GETTCLASS) tries to read the handle from this NULL pointer, causing a kernel panic.
Risk Assessment
A local user with CAP_NET_ADMIN in a network namespace (or unprivileged if unprivileged user namespaces are enabled) can intentionally trigger a kernel panic, leading to a denial of service (DoS) on the entire system.
Recommendation
Apply the official kernel patch immediately, which replaces NULL with &noop_qdisc in taprio_graft() and updates the corresponding checks in data paths. If the patch is unavailable, temporarily disable CONFIG_NET_SCH_TAPRIO or restrict TAPRIO qdisc creation for unprivileged users.
Related vulnerabilities
- CVE-2026-108860Critical
BotSharp through 5.2.0 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to forge bearer tokens using the hard-coded Jwt:Key in WebStarter appsettings.json. Attackers can sign tokens with the committed HMAC secret and fixed botsharp issuer and audience to impersonate any known user, including administrators, on Authorize-protected API routes.
- CVE-2026-108753Critical
Agnaistic agnai through 1.0.555 contains a hard-coded credentials vulnerability in self-host.docker-compose.yml, which sets a fixed admin password and public JWT secret. Unauthenticated attackers can log in as admin or sign their own JWT with admin: true to impersonate users, reset passwords, and change server configuration.
- CVE-2026-108576Critical
A vulnerability was found in TOZED X300 up to 6.01.3. This vulnerability affects the function process_ping of the component IPPingDiagnostics Handler. The manipulation of the argument Host results in os command injection. The attack can be launched remotely. The vendor was contacted early about this disclosure but did not respond in any way.
- CVE-2026-86717Critical
The Insurify WordPress plugin through 1.0 does not have authorisation and nonce checks on one of its AJAX actions, allowing unauthenticated users to delete arbitrary WordPress options, which can take the site offline and strip every user of their role.
- CVE-2026-86706Critical
The Quick quotes WordPress plugin through 1.0.0 does not perform any capability or nonce check on one of its AJAX actions and lets the caller choose which option is written, allowing unauthenticated users to alter arbitrary site settings and to make the site unavailable.
- CVE-2026-85121Critical
The Insurify WordPress plugin through 1.0 does not have authorisation and nonce checks on one of its AJAX actions, allowing unauthenticated users to create and overwrite arbitrary WordPress options with request data, which can take the site offline and deactivate all of its Insurify WordPress plugin through 1.0.
- CVE-2026-85118Critical
The AI Content Generator Marketing WordPress plugin through 1.0.0 does not enforce a nonce or capability check on some of its AJAX actions, allowing unauthenticated users to update and delete arbitrary WordPress options, which can be used to gain administrator access to the site.
- CVE-2026-84737Critical
The Freeton WP WordPress plugin through 1.0.0 does not correctly validate the activation code when authenticating a user, allowing unauthenticated attackers to log in as any user whose email address they know, including administrators.
- CVE-2026-84734Critical
The Mindstien Quick Login WordPress plugin through 1.0 does not correctly validate a value supplied in the request against the visitor's own session before authenticating them, allowing unauthenticated attackers to obtain a session as the administrator account the Mindstien Quick Login WordPress plugin through 1.0 is configured with.
- CVE-2026-84254Critical
The click5 CRM add-on to Contact Form 7 WordPress plugin through 1.0.4 does not have authorisation and CSRF checks when updating options via a REST endpoint, and does not ensure that the option to be updated belongs to the click5 CRM add-on to Contact Form 7 WordPress plugin through 1.0.4. As a result, unauthenticated attackers could change arbitrary blog options, allowing them to create a new administrator account and take over the site.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net/sched: taprio: fix NULL pointer dereference in class dump When a TAPRIO child qdisc is deleted via RTM_DELQDISC, taprio_graft() is called with new == NULL and stores NULL into q->qdiscs[cl - 1]. Subsequent RTM_GETTCLASS dump operations walk all classes via taprio_walk() and call taprio_dump_class(), which calls taprio_leaf() returning the NULL pointer, then dereferences it to read child->handle, causing a kernel NULL pointer dereference. The bug is reachable with namespace-scoped CAP_NET_ADMIN on any kernel with CONFIG_NET_SCH_TAPRIO enabled. On systems with unprivileged user namespaces enabled, an unprivileged local user can trigger a kernel panic by creating a taprio qdisc inside a new network namespace, grafting an explicit child qdisc, deleting it, and requesting a class dump. The RTM_GETTCLASS dump itself requires no capability. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:taprio_dump_class (net/sched/sch_taprio.c:2478) Call Trace: <TASK> tc_fill_tclass (net/sched/sch_api.c:1966) qdisc_class_dump (net/sched/sch_api.c:2326) taprio_walk (net/sched/sch_taprio.c:2514) tc_dump_tclass_qdisc (net/sched/sch_api.c:2352) tc_dump_tclass_root (net/sched/sch_api.c:2370) tc_dump_tclass (net/sched/sch_api.c:2431) rtnl_dumpit (net/core/rtnetlink.c:6864) netlink_dump (net/netlink/af_netlink.c:2325) rtnetlink_rcv_msg (net/core/rtnetlink.c:6959) netlink_rcv_skb (net/netlink/af_netlink.c:2550) </TASK> Fix this by substituting &noop_qdisc when new is NULL in taprio_graft(), a common pattern used by other qdiscs (e.g., multiq_graft()) to ensure the q->qdiscs[] slots are never NULL. This makes control-plane dump paths safe without requiring individual NULL checks. Since the data-plane paths (taprio_enqueue and taprio_dequeue_from_txq) previously had explicit NULL guards that would drop/skip the packet cleanly, update those checks to test for &noop_qdisc instead. Without this, packets would reach taprio_enqueue_one() which increments the root qdisc's qlen and backlog before calling the child's enqueue; noop_qdisc drops the packet but those counters are never rolled back, permanently inflating the root qdisc's statistics. After this change *old can be a valid qdisc, NULL, or &noop_qdisc. Only call qdisc_put(*old) in the first case to avoid decreasing noop_qdisc's refcount, which was never increased.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS