CVE-2025-38528

bpf: Reject %p% format string in bprintf-like helpers

MEDIUM
5.5
CVSS Score
Published: August 16, 2025 at 11:12 AM UTC
Updated: October 15, 2026 at 10:18 PM UTC
2 products affected across 2 vendorsLinux KernelDebian Linux

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject %p% format string in bprintf-like helpers static const char fmt[] = "%p%"; bpf_trace_printk(fmt, sizeof(fmt)); The above BPF program isn't rejected and causes a kernel warning at runtime: Please remove unsupported %\x00 in format string WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0 This happens because bpf_bprintf_prepare skips over the second %, detected as punctuation, while processing %p. This patch fixes it by not skipping over punctuation. %\x00 is then processed in the next iteration and rejected.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.13 ≤ v < 5.15.1905.16 ≤ v < 6.1.1476.13 ≤ v < 6.15.86.2 ≤ v < 6.6.1006.7 ≤ v < 6.12.4048cac3f4a96ddf08df8e53809ed066de0dc939156.166.16 rc16.16 rc26.16 rc36.16 rc46.16 rc56.16 rc6
Vendor states this is fixed in 1c5f5fd47bbda17cb885fe6f03730702cd53d3f8 (fixed)
Vendor states this is fixed in 61d5fa45ed13e42af14c7e959baba9908b8ee6d4 (fixed)
Vendor states this is fixed in 6952aeace93f8c9ea01849efecac24dd3152c9c9 (fixed)
Vendor states this is fixed in 97303e541e12f1fea97834ec64b98991e8775f39 (fixed)
Vendor states this is fixed in e7be679124bae8cf4fa6e40d7e1661baddfb3289 (fixed)
Vendor states this is fixed in f8242745871f81a3ac37f9f51853d12854fd0b58 (fixed)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.15.190 (unaffected)
Vendor states this is fixed in 6.1.147 (unaffected)
Vendor states this is fixed in 6.12.40 (unaffected)
Vendor states this is fixed in 6.15.8 (unaffected)
Vendor states this is fixed in 6.16 (unaffected)
Vendor states this is fixed in 6.6.100 (unaffected)

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/1c5f5fd47bbda17cb885fe6f03730702cd53d3f8
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/61d5fa45ed13e42af14c7e959baba9908b8ee6d4
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6952aeace93f8c9ea01849efecac24dd3152c9c9
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/97303e541e12f1fea97834ec64b98991e8775f39
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/e7be679124bae8cf4fa6e40d7e1661baddfb3289
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f8242745871f81a3ac37f9f51853d12854fd0b58
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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