# What is CVE-2024-26641? > CVE-2024-26641 is a medium-severity flaw (CVSS 5.5) in Linux kernel, published on 18 March 2024. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 0.6%. If you run an affected version, plan in the vendor’s fix. Canonical page: https://www.precursorintelligence.com/what-is/cve-2024-26641 ## At a glance - **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle. - **Precursor Intelligence risk score:** 48 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes. - **Severity:** Medium (CVSS 5.5 out of 10) - **Known to be exploited:** No, not on the list of flaws known to be exploited today - **Chance of use in the next 30 days:** 0.6% (latest exploit-likelihood forecast) - **Published:** 18 March 2024 - **Record last updated:** 4 August 2026 - **Main product:** Linux kernel - **Affected products:** 14 ## What is CVE-2024-26641? In plain terms An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can take it offline. ### The official description In the Linux kernel, the following vulnerability has been resolved: ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv() syzbot found __ip6_tnl_rcv() could access unitiliazed data [1]. Call pskb_inet_may_pull() to fix this, and initialize ipv6h variable after this call as it can change skb->head. [1] BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321 __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321 ip6ip6_dscp_ecn_decapsulate+0x178/0x1b0 net/ipv6/ip6_tunnel.c:727 __ip6_tnl_rcv+0xd4e/0x1590 net/ipv6/ip6_tunnel.c:845 ip6_tnl_rcv+0xce/0x100 net/ipv6/ip6_tunnel.c:888 gre_rcv+0x143f/0x1870 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [inline] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5532 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646 netif_receive_skb_internal net/core/dev.c:5732 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5791 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2084 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x786/0x1200 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787 tun_alloc_skb drivers/net/tun.c:1531 [inline] tun_get_user+0x1e8a/0x66d0 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2084 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x786/0x1200 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 5034 Comm: syz-executor331 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ### What kind of flaw is it? - CWE-908: Use of Uninitialized Resource ### How an attack on it works - Where an attacker can be: Already on the device - How hard it is to pull off: Easy: no special conditions - Login needed first: An ordinary user account - Does someone have to click: No, nobody has to do anything - What an attacker gets: Can take it offline Severity vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` ## Is CVE-2024-26641 being exploited? Not that we know of It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.6%. That can change at any time, which is why we keep watching. Exploit likelihood over the last 7 days: 0.6%, 0.6%, 0.6%, 0.6%, 0.6%, 0.6%, 0.6%. ### Timeline - 18 March 2024: Published - 4 August 2026: Record last updated ### How Precursor Intelligence ranks it CVE-2024-26641 scores **48 out of 100 (Medium)**, with the action "Plan remediation". Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less: - Evidence it is being exploited: biggest factor - How severe it is: strong factor - How widely exposed it is: smaller factor - Threat activity around it: smaller factor 85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it. ## Who is affected by CVE-2024-26641? The published record lists 14 products. Versions are as published: "4.7 to before 5.10.210" means from 4.7 up to, but not including, 5.10.210. - [Linux kernel](https://www.precursorintelligence.com/product/linux/linux_kernel) by [Linux](https://www.precursorintelligence.com/vendors/linux) (Operating system): 4.7 to before 5.10.210, 5.11 to before 5.15.149, 5.16 to before 6.1.77, 6.2 to before 6.6.16, 6.7 to before 6.7.4, 6.8-rc1, 6.8-rc2 - [A150 Firmware](https://www.precursorintelligence.com/product/netapp/a150_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [A220 Firmware](https://www.precursorintelligence.com/product/netapp/a220_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [A800 Firmware](https://www.precursorintelligence.com/product/netapp/a800_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [A900 Firmware](https://www.precursorintelligence.com/product/netapp/a900_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Active Iq Unified Manager](https://www.precursorintelligence.com/product/netapp/active_iq_unified_manager) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified - [C190 Firmware](https://www.precursorintelligence.com/product/netapp/c190_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [C800 Firmware](https://www.precursorintelligence.com/product/netapp/c800_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Debian Linux](https://www.precursorintelligence.com/product/debian/debian_linux) by [Debian](https://www.precursorintelligence.com/vendors/debian) (Operating system): 10.0 - [Fas2720 Firmware](https://www.precursorintelligence.com/product/netapp/fas2720_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Fas2750 Firmware](https://www.precursorintelligence.com/product/netapp/fas2750_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Fas2820 Firmware](https://www.precursorintelligence.com/product/netapp/fas2820_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Fas9500 Firmware](https://www.precursorintelligence.com/product/netapp/fas9500_firmware) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Operating system): version not specified - [Ontap Select Deploy Administration Utility](https://www.precursorintelligence.com/product/netapp/ontap_select_deploy_administration_utility) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified ## How do I fix CVE-2024-26641? 1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list. 2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list. 3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in. 4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood. ### References - [git.kernel.org](https://git.kernel.org/stable/c/350a6640fac4b53564ec20aa3f4a0922cb0ba5e6) (Mailing list, Patch) - [git.kernel.org](https://git.kernel.org/stable/c/8d975c15c0cd744000ca386247432d57b21f9df0) (Mailing list, Patch) - [git.kernel.org](https://git.kernel.org/stable/c/a9bc32879a08f23cdb80a48c738017e39aea1080) (Mailing list, Patch) - [git.kernel.org](https://git.kernel.org/stable/c/af6b5c50d47ab43e5272ad61935d0ed2e264d3f0) (Mailing list, Patch) - [git.kernel.org](https://git.kernel.org/stable/c/c835df3bcc14858ae9b27315dd7de76370b94f3a) (Mailing list, Patch) - [git.kernel.org](https://git.kernel.org/stable/c/d54e4da98bbfa8c257bdca94c49652d81d18a4d8) (Mailing list, Patch) - [lists.debian.org](https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html) (Mailing list) - [security.netapp.com](https://security.netapp.com/advisory/ntap-20241108-0008/) (Third-party advisory) ## Questions ### What is CVE-2024-26641? CVE-2024-26641 is a medium-severity flaw in Linux kernel, published on 18 March 2024. An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can take it offline. ### How serious is CVE-2024-26641? It scores 5.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2024-26641 is 48 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle. ### Is CVE-2024-26641 being exploited? It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.6%. That can change at any time, which is why we keep watching. ### Which versions does CVE-2024-26641 affect? For Linux kernel: 4.7 to before 5.10.210, 5.11 to before 5.15.149, 5.16 to before 6.1.77, 6.2 to before 6.6.16, 6.7 to before 6.7.4, 6.8-rc1 and 1 more. The record lists 14 products in all, each with its versions, under "Who is affected" on this page. ### How do I fix CVE-2024-26641? Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. ## Does CVE-2024-26641 affect you? Precursor Intelligence keeps checking for you: - **Tell us what you run.** Pick your software from a list, or let us work it out from your website. - **We match it to every flaw.** Over 400,000 published flaws, checked against your list. - **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it. - **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools. Start free (no card, nothing to install): https://www.precursorintelligence.com/register Book a demo: https://www.precursorintelligence.com/contact