Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7 bpf lib/vsprintf.c bpf_trace_printk fmt[] format string

CVSS Meta Temp Score
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CTI Interest Score
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6.6$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7. This vulnerability affects the function bpf_trace_printk in the library lib/vsprintf.c of the component bpf. This manipulation of the argument fmt[] causes format string. The identification of this vulnerability is CVE-2025-38528. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.146/6.6.99/6.12.39/6.15.7. It has been declared as critical. Affected by this vulnerability is the function bpf_trace_printk in the library lib/vsprintf.c of the component bpf. The manipulation of the argument fmt[] with an unknown input leads to a format string vulnerability. The CWE definition for the vulnerability is CWE-134. The product uses a function that accepts a format string as an argument, but the format string originates from an external source. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2025-38528 since 04/16/2025. The exploitation appears to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 265749 (SUSE SLED15 / SLES15 Security Update : kernel (SUSE-SU-2025:03290-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.147, 6.6.100, 6.12.40 or 6.15.8 eliminates this vulnerability. Applying the patch 61d5fa45ed13e42af14c7e959baba9908b8ee6d4/e7be679124bae8cf4fa6e40d7e1661baddfb3289/6952aeace93f8c9ea01849efecac24dd3152c9c9/1c5f5fd47bbda17cb885fe6f03730702cd53d3f8/f8242745871f81a3ac37f9f51853d12854fd0b58 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (265749), EUVD (EUVD-2025-26113) and CERT Bund (WID-SEC-2025-1858). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell NetWorker
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM
  • IBM Security Verify Access

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Format string
CWE: CWE-134 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 265749
Nessus Name: SUSE SLED15 / SLES15 Security Update : kernel (SUSE-SU-2025:03290-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.147/6.6.100/6.12.40/6.15.8
Patch: 61d5fa45ed13e42af14c7e959baba9908b8ee6d4/e7be679124bae8cf4fa6e40d7e1661baddfb3289/6952aeace93f8c9ea01849efecac24dd3152c9c9/1c5f5fd47bbda17cb885fe6f03730702cd53d3f8/f8242745871f81a3ac37f9f51853d12854fd0b58

Timelineinfo

04/16/2025 CVE reserved
08/16/2025 +122 days Advisory disclosed
08/16/2025 +0 days VulDB entry created
01/30/2026 +167 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38528 (🔒)
GCVE (CVE): GCVE-0-2025-38528
GCVE (VulDB): GCVE-100-320389
EUVD: 🔒
CERT Bund: WID-SEC-2025-1858 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 08/16/2025 14:38
Updated: 01/30/2026 18:44
Changes: 08/16/2025 14:38 (61), 09/24/2025 05:28 (2), 09/28/2025 08:53 (7), 10/03/2025 13:23 (1), 10/12/2025 18:03 (1), 11/01/2025 19:49 (1), 01/08/2026 01:02 (12), 01/08/2026 20:38 (1), 01/30/2026 18:44 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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