CVE-2025-38718 [High] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: sctp: linearize cloned gso packets in sctp_rcv A cloned head skb still shares these frag skbs in fraglist with the original head skb. It's not safe to access these frag skbs. syzbot reported two use-of-uninitialized-memory bugs caused by this: BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122 __release_sock+0x1da/0x330 net/core/sock.c:3106 release_sock+0x6b/0x250 net/core/sock.c:3660 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885 sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:718 [inline] and BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] This patch fixes it by linearizing cloned gso packets in sctp_rcv().

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-01-10	0.06%	0.02%	-0.04%
2	2026-01-04	0.02%	0.06%	+0.04%
3	2025-09-05	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-01-10

0.06%

0.02%

-0.04%

2026-01-04

0.02%

0.06%

+0.04%

2025-09-05

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

OS Trackers for CVE-2025-38718

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2025-38718 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-38718
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-38718
`suse`	medium	CVE-2025-38718 severity moderate: SUSE including 558 source package names (13.2-6.19:libjitterentropy3-3.4.1-3.1, 13.2-6.19:libopenssl3-3.1.4-6.1, …), 1083 product×package rows across 213 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (213 product lines)): Fixed 816, Known Affected 231, First Fixed 21, Known Not Affected 15.	https://www.suse.com/security/cve/CVE-2025-38718/
`ubuntu`	medium	CVE-2025-38718 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 177, released 150, needed 43, not-affected 24, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-38718

Affected software / configurations for CVE-2025-38718

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 4.8, < 5.4.297	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.241	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.190	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.6.103	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.43	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.15.11	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.16, < 6.16.2	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.17	cpe:2.3:o:linux:linux_kernel:6.17:rc1::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2025-38718

URL	Tags
https://git.kernel.org/stable/c/03d0cc6889e02420125510b5444b570f4bbf53d5	Patch
https://git.kernel.org/stable/c/1bd5214ea681584c5886fea3ba03e49f93a43c0e	Patch
https://git.kernel.org/stable/c/4506bcaabe004d07be8ff09116a3024fbd6aa965	Patch
https://git.kernel.org/stable/c/7d757f17bc2ef2727994ffa6d5d6e4bc4789a770	Patch
https://git.kernel.org/stable/c/cd0e92bb2b7542fb96397ffac639b4f5b099d0cb	Patch
https://git.kernel.org/stable/c/d0194e391bb493aa6cec56d177b14df6b29188d5	Patch
https://git.kernel.org/stable/c/ea094f38d387d1b0ded5dee4a3e5720aa4ce0139	Patch
https://git.kernel.org/stable/c/fc66772607101bd2030a4332b3bd0ea3b3605250	Patch
https://git.kernel.org/stable/c/fd60d8a086191fe33c2d719732d2482052fa6805	Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html	Mailing List Third Party Advisory

URL

CVE-2025-38718 | sctp: linearize cloned gso packets in sctp_rcv

Exploit prediction scoring system (EPSS) score for CVE-2025-38718

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38718

Weakness enumeration for CVE-2025-38718

OS Trackers for CVE-2025-38718

Affected software / configurations for CVE-2025-38718

References for CVE-2025-38718