CVE-2026-23095: linux
Vulnerability summary
CVE-2026-23095 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 45 · Related 39Timeline
- 04-02-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: gue: Fix skb memleak with inner IP protocol 0. syzbot reported skb memleak below. [0] The repro generated a GUE packet with its inner protocol 0. gue_udp_recv() returns -guehdr->proto_ctype for "resubmit" in ip_protocol_deliver_rcu(), but this only works with non-zero protocol number. Let's drop such packets. Note that 0 is a valid number (IPv6 Hop-by-Hop Option). I think it is not practical to encap HOPOPT in GUE, so once someone starts to complain, we could pass down a resubmit flag pointer to distinguish two zeros from the upper layer: * no error * resubmit HOPOPT [0] BUG: memory leak unreferenced object 0xffff888109695a00 (size 240): comm "syz.0.17", pid 6088, jiffies 4294943096 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 40 c2 10 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace (crc a84b336f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5270 __build_skb+0x23/0x60 net/core/skbuff.c:474 build_skb+0x20/0x190 net/core/skbuff.c:490 __tun_build_skb drivers/net/tun.c:1541 [inline] tun_build_skb+0x4a1/0xa40 drivers/net/tun.c:1636 tun_get_user+0xc12/0x2030 drivers/net/tun.c:1770 tun_chr_write_iter+0x71/0x120 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0xa7/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.30%
Chance of exploitation in the next 30 days
Percentile
21%
Versus all other CVEs
30-day change
+0.05 pp
From 0.25% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu156 products
- linuxAll versions (No fix recorded) | < 5.15.0-176.186 | < 6.8.0-117.117
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1105.112 | < 6.8.0-1055.58
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < 886f186328b718400dbf79e1bc8cbcbd710ab766 | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < 380a82d36e37db49fd41ecc378c22fd29392e96a | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < 536f5bbc322eb1e175bdd1ced22b236a951c4d8f | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < f87b9b7a618c82e7465e872eb10e14c803871892 | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < ce569b389a5c78d64788a5ea94560e17fa574b35 | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < 5437a279804ced8088cabb945dba88a26d828f8c | ≥ 37dd0247797b168ad1cc7f5dbec825a1ee66535b, < 9a56796ad258786d3624eef5aefba394fc9bdded | 3.18
- linux_kernel≥ 3.18, < 5.10.249 | ≥ 5.11, < 5.15.199 | ≥ 5.16, < 6.1.162 | ≥ 6.2, < 6.6.122 | ≥ 6.7, < 6.12.68 | ≥ 6.13, < 6.18.8 | 6.19:rc1 | 6.19:rc2 | 6.19:rc3 | 6.19:rc4 | 6.19:rc5 | 6.19:rc6
Debian1 product
- linux< 6.1.162-1 | < 6.12.69-1 | < 6.18.8-1
3 vendors · 159 products
