CVE-2025-38639 | netfilter: xt_nfacct: don't assume acct name is null-terminated

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_nfacct: don't assume acct name is null-terminated BUG: KASAN: slab-out-of-bounds in .. lib/vsprintf.c:721 Read of size 1 at addr ffff88801eac95c8 by task syz-executor183/5851 [..] string+0x231/0x2b0 lib/vsprintf.c:721 vsnprintf+0x739/0xf00 lib/vsprintf.c:2874 [..] nfacct_mt_checkentry+0xd2/0xe0 net/netfilter/xt_nfacct.c:41 xt_check_match+0x3d1/0xab0 net/netfilter/x_tables.c:523 nfnl_acct_find_get() handles non-null input, but the error printk relied on its presence.

Published: 2025-08-22 Last update: 2026-01-07 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-38639 is rated Low Risk (23.7/100): CVSS Medium 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-2025-38639

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 2026-01-08 0.06% 0.02% -0.04%
2 2025-12-22 0.02% 0.06% +0.04%
3 2025-08-23 0.02%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38639

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-38639

OS Trackers for CVE-2025-38639

vendor priority summary link
debian not yet assigned CVE-2025-38639 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-2025-38639
redhat medium https://access.redhat.com/security/cve/CVE-2025-38639
suse medium CVE-2025-38639 severity moderate: SUSE including 481 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, …), 966 product×package rows across 198 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (198 product lines)): Fixed 704, Known Affected 231, First Fixed 21, Known Not Affected 10. https://www.suse.com/security/cve/CVE-2025-38639/
ubuntu medium CVE-2025-38639 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-2025-38639

Affected software / configurations for CVE-2025-38639

Vendor Product Version Raw CPE
linux linux_kernel >= 3.3, < 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:*:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38639

URL Tags
https://git.kernel.org/stable/c/58004aa21e79addaf41667bfe65e93ec51653f18 Patch
https://git.kernel.org/stable/c/58007fc7b94fb2702000045ff401eb7f5bde7828 Patch
https://git.kernel.org/stable/c/66d41268ede1e1b6e71ba28be923397ff0b2b9c3 Patch
https://git.kernel.org/stable/c/7c1ae471da69c09242834e956218ea6a42dd405a Patch
https://git.kernel.org/stable/c/b10cfa2de13d28ddd03210eb234422b7ec92725a Patch
https://git.kernel.org/stable/c/bf58e667af7d96c8eb9411f926a0a0955f41ce21 Patch
https://git.kernel.org/stable/c/df13c9c6ce1d55c31d1bd49db65a7fbbd86aab13 Patch
https://git.kernel.org/stable/c/e021a1eee196887536a6630c5492c23a4c78d452 Patch
https://git.kernel.org/stable/c/e18939176e657a3a20bfbed357b8c55a9f82aba3 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
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