Linux Kernel up to 6.17-rc4 batadv_nc_skb_decode_packet out-of-bounds write

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.17-rc4. It has been classified as critical. Affected by this issue is the function batadv_nc_skb_decode_packet. Performing a manipulation results in out-of-bounds write. This vulnerability is cataloged as CVE-2025-39839. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.17-rc4. This affects the function batadv_nc_skb_decode_packet. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: batman-adv: fix OOB read/write in network-coding decode batadv_nc_skb_decode_packet() trusts coded_len and checks only against skb->len. XOR starts at sizeof(struct batadv_unicast_packet), reducing payload headroom, and the source skb length is not verified, allowing an out-of-bounds read and a small out-of-bounds write. Validate that coded_len fits within the payload area of both destination and source sk_buffs before XORing.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-39839 since 04/16/2025. The exploitability is told 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 06/24/2026).

The vulnerability scanner Nessus provides a plugin with the ID 265710 (Debian dsa-6008 : ata-modules-6.12.31-armmp-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46, 6.16.6 or 6.17-rc5 eliminates this vulnerability. Applying the patch 30fc47248f02b8a14a61df469e1da4704be1a19f/1e36c6c8dc8023b4bbe9a16e819f9998b9b6a183/5d334bce9fad58cf328d8fa14ea1fff855819863/dce6c2aa70e94c04c523b375dfcc664d7a0a560a/bb37252c9af1cb250f34735ee98f80b46be3cef1/20080709457bc1e920eb002483d7d981d9b2ac1c/a67c6397fcb7e842d3c595243049940970541c48/d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087 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 (265710) and CERT Bund (WID-SEC-2025-2099). 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
• IBM QRadar SIEM
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Dell Secure Connect Gateway
• Dell NetWorker
• Dell ECS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.298
• 5.10.242
• 5.15.191
• 6.1.150
• 6.6.104
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.16.0
• 6.16.1
• 6.16.2
• 6.16.3
• 6.16.4
• 6.16.5
• 6.17-rc1
• 6.17-rc2
• 6.17-rc3
• 6.17-rc4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.6
VulDB Meta Temp Score: 7.4

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

NVD Base Score: 7.1
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 265710
Nessus Name: Debian dsa-6008 : ata-modules-6.12.31-armmp-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.299/5.10.243/5.15.192/6.1.151/6.6.105/6.12.46/6.16.6/6.17-rc5
Patch: 30fc47248f02b8a14a61df469e1da4704be1a19f/1e36c6c8dc8023b4bbe9a16e819f9998b9b6a183/5d334bce9fad58cf328d8fa14ea1fff855819863/dce6c2aa70e94c04c523b375dfcc664d7a0a560a/bb37252c9af1cb250f34735ee98f80b46be3cef1/20080709457bc1e920eb002483d7d981d9b2ac1c/a67c6397fcb7e842d3c595243049940970541c48/d77b6ff0ce35a6d0b0b7b9581bc3f76d041d4087

Timelineinfo

04/16/2025 CVE reserved
09/19/2025 +156 days Advisory disclosed
09/19/2025 +0 days VulDB entry created
06/24/2026 +278 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39839 (🔒)
GCVE (CVE): GCVE-0-2025-39839
GCVE (VulDB): GCVE-100-325029
CERT Bund: WID-SEC-2025-2099 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/19/2025 18:09
Updated: 06/24/2026 09:39
Changes: 09/19/2025 18:09 (58), 09/23/2025 18:24 (2), 10/20/2025 19:02 (7), 11/03/2025 12:45 (1), 11/11/2025 22:33 (1), 11/29/2025 06:03 (1), 12/22/2025 10:25 (1), 01/20/2026 16:55 (11), 06/24/2026 09:39 (1)
Complete: 🔍
Cache ID: 216::103

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Discussion

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