CVE Watch14 jul 2026

CVE-2026-22977

In the Linux kernel, the following vulnerability has been resolved: net: sock: fix hardened usercopy panic in sock_recv_errqueue skbuff_fc

CVSS

5.5

Medio

EPSS

0.1%

KEV

—

Exploit Today

0-100

Publicado: 21 ene 2026 · Última mod.: 14 jul 2026 · CWE-476

EPSS · 30d

0.1%EPSS · 30 días0.1%

2026-08-032026-08-31

Descripción técnica

In the Linux kernel, the following vulnerability has been resolved: net: sock: fix hardened usercopy panic in sock_recv_errqueue skbuff_fclone_cache was created without defining a usercopy region, [1] unlike skbuff_head_cache which properly whitelists the cb[] field. [2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is enabled and the kernel attempts to copy sk_buff.cb data to userspace via sock_recv_errqueue() -> put_cmsg(). The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone() (from skbuff_fclone_cache) [1] 2. The skb is cloned via skb_clone() using the pre-allocated fclone [3] 3. The cloned skb is queued to sk_error_queue for timestamp reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE) 5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb [4] 6. __check_heap_object() fails because skbuff_fclone_cache has no usercopy whitelist [5] When cloned skbs allocated from skbuff_fclone_cache are used in the socket error queue, accessing the sock_exterr_skb structure in skb->cb via put_cmsg() triggers a usercopy hardening violation: [ 5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)! [ 5.382796] kernel BUG at mm/usercopy.c:102! [ 5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 #7 [ 5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 5.384903] RIP: 0010:usercopy_abort+0x6c/0x80 [ 5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490 [ 5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246 [ 5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74 [ 5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0 [ 5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74 [ 5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001 [ 5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00 [ 5.384903] FS: 0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000 [ 5.384903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0 [ 5.384903] PKRU: 55555554 [ 5.384903] Call Trace: [ 5.384903] <TASK> [ 5.384903] __check_heap_object+0x9a/0xd0 [ 5.384903] __check_object_size+0x46c/0x690 [ 5.384903] put_cmsg+0x129/0x5e0 [ 5.384903] sock_recv_errqueue+0x22f/0x380 [ 5.384903] tls_sw_recvmsg+0x7ed/0x1960 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? schedule+0x6d/0x270 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? mutex_unlock+0x81/0xd0 [ 5.384903] ? __pfx_mutex_unlock+0x10/0x10 [ 5.384903] ? __pfx_tls_sw_recvmsg+0x10/0x10 [ 5.384903] ? _raw_spin_lock_irqsave+0x8f/0xf0 [ 5.384903] ? _raw_read_unlock_irqrestore+0x20/0x40 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 The crash offset 296 corresponds to skb2->cb within skbuff_fclones: - sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 - offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 = 272 + 24 (inside sock_exterr_skb.ee) This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure. [1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885 [2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104 [3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566 [4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491 [5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719

Referencias oficiales

CVEs relacionados

CVECVSSEPSSKEVRExplotTítuloVis.

CVE-2026-828035.3 MED

—

——0A vulnerability has been found in armink struct2json 1.0. This affects the function S2J_STRUCT_GET_string_ELEMENT in the library struct2json/inc/s2jdef.h of the component JSON Deserialization. The manipulation of the argument valuestring leads to null pointer dereference. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.1d CVE-2026-825884.3 MED

23.3%

——7A vulnerability was identified in Open5GS up to 2.7.7. This issue affects some unknown processing of the file src/amf/namf-handler.c of the component Transfer Endpoint. Such manipulation leads to null pointer dereference. The attack can be launched remotely. Upgrading to version 2.8.0 is capable of addressing this issue. The name of the patch is abf8a836564b966b5141110fc25ed413c4f17522. Upgrading the affected component is advised.2d CVE-2026-772174.9 MED

36.1%

——11PLANET GS-4210-16P2S firmware before 3.441b260626 contains authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the radKey, radKey_0, radDftParamKey, radName, and radIp POST parameters into fixed-size stack buffers without length validation, and additionally dereferences radName and radIp without verifying their presence in the request. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.1d CVE-2026-751254.9 MED

32.2%

——10PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated null pointer dereference vulnerability in /cgi-bin/dispatcher.cgi. The web_poe_alive_rmtip_post handler dereferences the rmtIP parameter without verifying its presence. A remote authenticated attacker can send a crafted request omitting the rmtIP parameter to cause the CGI process to dereference a null pointer and crash, resulting in denial of service of the web management interface.4d CVE-2026-540845.3 MED

1.7%

——1Wazuh is an open-source security platform providing unified XDR and SIEM protection for endpoints and cloud workloads. In versions 4.0.0 through 4.14.6, a malicious or man-in-the-middle enrollment manager can crash a Wazuh agent during enrollment by returning a malformed key response with fewer than four fields, causing a NULL pointer dereference. The w_enrollment_process_agent_key() routine splits the manager-provided key into four space-separated fields but does not verify that all fields are present before passing them to validators. Because OS_StrBreak() leaves missing trailing entries as NULL and OS_IsValidName() calls strlen() on its argument without a NULL check, a response such as OSSEC K:'1' reaches OS_IsValidName(NULL) and terminates the agent process. Since Wazuh permits enrollment against an unverified manager when no CA certificate is configured, an attacker operating a rogue manager or intercepting the enrollment flow can deterministically crash agents, resulting in denial of service. This issue is fixed in version 4.14.7.4d CVE-2026-383447.5 ALT

4.5%

——1A NULL pointer dereference in the get_min_buffer_size function (/libswscale/slice.c) of FFmpeg N-122528-gdd2976b9e1 allows attackers to cause a Denial of Service (DoS) via supplying a crafted video file.1d