CVE-2025-38574 | pptp: ensure minimal skb length in pptp_xmit()

In the Linux kernel, the following vulnerability has been resolved: pptp: ensure minimal skb length in pptp_xmit() Commit aabc6596ffb3 ("net: ppp: Add bound checking for skb data on ppp_sync_txmung") fixed ppp_sync_txmunge() We need a similar fix in pptp_xmit(), otherwise we might read uninit data as reported by syzbot. BUG: KMSAN: uninit-value in pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2290 [inline] ppp_input+0x1d6/0xe60 drivers/net/ppp/ppp_generic.c:2314 pppoe_rcv_core+0x1e8/0x760 drivers/net/ppp/pppoe.c:379 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 pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2709

Published: 2025-08-19 Last update: 2026-01-09 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-38574 is rated Low Risk (33/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38574

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-10 0.06% 0.02% -0.04%
2 2025-12-19 0.02% 0.06% +0.04%
3 2025-08-20 0.02%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38574

CVSS metrics for this CVE.

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]

Weakness enumeration for CVE-2025-38574

OS Trackers for CVE-2025-38574

vendor priority summary link
debian not yet assigned CVE-2025-38574 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-2025-38574
redhat medium https://access.redhat.com/security/cve/CVE-2025-38574
suse medium CVE-2025-38574 severity moderate: SUSE including 475 source package names (2.1.3-6.80:kernel-default-base-6.4.0-35.1.21.12, 2.1.3-7.57:kernel-default-6.4.0-35.1, …), 956 product×package rows across 196 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (196 product lines)): Fixed 704, Known Affected 231, First Fixed 21. https://www.suse.com/security/cve/CVE-2025-38574/
ubuntu medium CVE-2025-38574 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 165, released 165, needed 45, not-affected 18, needs-triage 2, pending 2. https://ubuntu.com/security/CVE-2025-38574

Affected software / configurations for CVE-2025-38574

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.13, < 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, < 6.1.148 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.102 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.42 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.15.10 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.16, < 6.16.1 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 2.6.12 cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*
linux linux_kernel 2.6.12 cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*
linux linux_kernel 2.6.12 cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*
linux linux_kernel 2.6.12 cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*
linux linux_kernel 2.6.12 cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38574

URL Tags
https://git.kernel.org/stable/c/1a04db0fd75cb6034fc27a56b67b3b8b9022a98c Patch
https://git.kernel.org/stable/c/26672f1679b143aa34fca0b6046b7fd0c184770d Patch
https://git.kernel.org/stable/c/5005d24377378a20e5c0e53052fc4ebdcdcbc611 Patch
https://git.kernel.org/stable/c/504cc4ab91073d2ac7404ad146139f86ecee7193 Patch
https://git.kernel.org/stable/c/5de7513f38f3c19c0610294ee478242bea356f8c Patch
https://git.kernel.org/stable/c/97b8c5d322c5c0038cac4bc56fdbe237d0be426f Patch
https://git.kernel.org/stable/c/b7dcda76fd0615c0599c89f36873a6cd48e02dbb Patch
https://git.kernel.org/stable/c/de9c4861fb42f0cd72da844c3c34f692d5895b7b Patch
https://git.kernel.org/stable/c/ea99b88b1999ebcb24d5d3a6b7910030f40d3bba Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Mailing List Third Party Advisory
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