Kernel heap disclosure via uncleared J1939 buffer
Published Aug 28, 2026 · Updated Aug 28, 2026
Information disclosure in the Linux J1939 transport allows local users to read residual kernel heap data through a crafted CAN session. j1939_session_fresh_new() exposes the full alloc_skb() data area without clearing it, so recvmsg returns its untouched tail. Reachability requires a J1939 socket and crafted RTS or BAM control data that marks a partially filled message complete; disclosure is limited to residual slab bytes in that receive buffer.
Summary
What happened
Information disclosure in the Linux J1939 transport allows local users to read residual kernel heap data through a crafted CAN session. j1939_session_fresh_new() exposes the full alloc_skb() data area without clearing it, so recvmsg returns its untouched tail. Reachability requires a J1939 socket and crafted RTS or BAM control data that marks a partially filled message complete; disclosure is limited to residual slab bytes in that receive buffer.
The record
- CVE
- CVE-2026-80707
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1005
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.4
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <038bad8e16c2e28acf31f0b527a816fb23a57269
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <194d67e92197eb820f4c2c6605d9721333b3eba0
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <348818277a3646d5b9fa60c9d20c00dc4bc86832
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <8604a3b81b9d0ceaf04fee5f52e701f623a179f9
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <bbfa49d1e287de44994955b44d19281be3195b44
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <d5b3613c7d69d8dcb4dd6704f1f463198ce9f6cf
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <eb96c58907922546e415e545fe9a14ea63b02719
- Affected versionversion=9d71dd0c70099914fcd063135da3c580865e924c <f3e120a34b336079479fa10f706f0636eaa6e751
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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