CVE-2026-64436 : Detail

CVE-2026-64436

7.1
/
High
Overflow
Local
2026-07-25
10h17 +00:00
2026-09-03
18h19 +00:00
Notifications for a CVE
Stay informed of any changes for a specific CVE.
Notifications manage

CVE Descriptions

In the Linux kernel, the following vulnerability has been resolved: net: af_key: initialize alg_key_len for IPComp states pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by allocating x->calg and copying only the algorithm name: x->calg = kmalloc_obj(*x->calg); if (!x->calg) { err = -ENOMEM; goto out; } strcpy(x->calg->alg_name, a->name); x->props.calgo = sa->sadb_sa_encrypt; Unlike the authentication (x->aalg) and encryption (x->ealg) branches of the same function, the compression branch never initializes calg->alg_key_len. IPComp carries no key and the allocation only reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field is left containing uninitialized slab data. calg->alg_key_len is later used as a length by xfrm_algo_clone() when an IPComp state is cloned during XFRM_MSG_MIGRATE: xfrm_state_migrate() xfrm_state_clone_and_setup() x->calg = xfrm_algo_clone(orig->calg); kmemdup(orig, xfrm_alg_len(orig)); where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With a non-zero garbage alg_key_len, kmemdup() reads past the end of the 68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating it triggers (net-next, KASAN, init_on_alloc=0): BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60 Read of size 4164 at addr ff11000025a74980 by task diag2/9287 CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1 Call Trace: dump_stack_lvl+0x10e/0x1f0 print_report+0xf7/0x600 kasan_report+0xe4/0x120 kasan_check_range+0x105/0x1b0 __asan_memcpy+0x23/0x60 kmemdup_noprof+0x44/0x60 xfrm_state_migrate+0x70a/0x1da0 xfrm_migrate+0x753/0x18a0 xfrm_do_migrate+0xb47/0xf10 xfrm_user_rcv_msg+0x411/0xb50 netlink_rcv_skb+0x158/0x420 xfrm_netlink_rcv+0x71/0x90 netlink_unicast+0x584/0x850 netlink_sendmsg+0x8b0/0xdc0 ____sys_sendmsg+0x9f7/0xb90 ___sys_sendmsg+0x134/0x1d0 __sys_sendmsg+0x16d/0x220 do_syscall_64+0x116/0x7d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task 9287: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 pfkey_add+0x2652/0x2ea0 pfkey_process+0x6d0/0x830 pfkey_sendmsg+0x42c/0x850 __sys_sendto+0x461/0x4b0 __x64_sys_sendto+0xe0/0x1c0 do_syscall_64+0x116/0x7d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ff11000025a74980 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of allocated 68-byte region [ff11000025a74980, ff11000025a749c4) Depending on the uninitialized value the same field can instead request an oversized kmemdup() allocation and make the migration clone fail. The XFRM netlink path is not affected: verify_one_alg() rejects an XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via XFRM_MSG_NEWSA is always self-consistent. Initialize calg->alg_key_len to 0, matching the aalg/ealg branches.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-125 Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 7.1 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Local

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities.

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (including) 2.6.21 To (excluding) 5.10.261

Linux>>Linux_kernel >> Version From (including) 5.11 To (excluding) 5.15.212

Linux>>Linux_kernel >> Version From (including) 5.16 To (excluding) 6.1.178

Linux>>Linux_kernel >> Version From (including) 6.2 To (excluding) 6.6.145

Linux>>Linux_kernel >> Version From (including) 6.7 To (excluding) 6.12.96

Linux>>Linux_kernel >> Version From (including) 6.13 To (excluding) 6.18.39

Linux>>Linux_kernel >> Version From (including) 6.19 To (excluding) 7.1.4

References