CVE-2026-64047
What it is
In the Linux kernel, the following vulnerability has been resolved: net: tls: fix off-by-one in sg_chain entry count for wrapped sk_msg ring When an sk_msg scatterlist ring wraps (sg.end < sg.start), tls_push_record() chains the tail portion of the ring to the head using sg_chain(). An extra entry in the sg array is reserved for this: struct sk_msg_sg { [...] /* The extra two elements: * 1) used for chaining the front and sections when the list becomes * partitioned (e.g. end < start). The crypto APIs require the * chaining; * 2) to chain tailer SG entries after the message. */ struct scatterlist data[MAX_MSG_FRAGS + 2]; The current code uses MAX_SKB_FRAGS + 1 as the ring size: sg_chain(&msg_pl->sg.data[msg_pl->sg.start], MAX_SKB_FRAGS - msg_pl->sg.start + 1, msg_pl->sg.data); This places the chain pointer at sg_chain(data[start], (MAX_SKB_FRAGS - msg_start + 1) .. = &data[start] + (MAX_SKB_FRAGS - msg_start + 1) - 1 = data[start + (MAX_SKB_FRAGS - start + 1) - 1] = data[MAX_SKB_FRAGS] instead of the true last entry. This is likely due to a "race" of the commit under Fixes landing close to commit 031097d9e079 ("bpf: sk_msg, zap ingress queue on psock down") Convert to ARRAY_SIZE and drop the data[start] / - start (as suggested by Sabrina).
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-193
- Record status
- Modified
Affected
- Linux Kernel < 5.5
- Linux Kernel < 5.10.258
- Linux Kernel < 5.15.209
- Linux Kernel < 6.1.175
- Linux Kernel < 6.6.142
- Linux Kernel < 6.12.92
- Linux Kernel < 6.18.34
- Linux Kernel < 7.0.11
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-64047.md and follow it. Check whether this project is affected by CVE-2026-64047. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/131ef12057d92b77b636321b7849c69222405a97
- https://git.kernel.org/stable/c/285943c6e7ca309bbea84b253745154241d9788a
- https://git.kernel.org/stable/c/2fb0dc7e0099686c4e9d2732745d8a31b18c3628
- https://git.kernel.org/stable/c/47110c3a9ac247b688657337f5981efcfcb240dc
- https://git.kernel.org/stable/c/66339b71f105e6f83e0da3b9583d95077534fe1d
- https://git.kernel.org/stable/c/73963a375885d5ccb7def39fd0b4f542e0f343dd
- https://git.kernel.org/stable/c/84158c2997159df4a0d70cd9c46774512d32a522
- https://git.kernel.org/stable/c/eca989eab4b2599dcb02f72140a7c08f08838520
References
- https://git.kernel.org/stable/c/131ef12057d92b77b636321b7849c69222405a97
- https://git.kernel.org/stable/c/285943c6e7ca309bbea84b253745154241d9788a
- https://git.kernel.org/stable/c/2fb0dc7e0099686c4e9d2732745d8a31b18c3628
- https://git.kernel.org/stable/c/47110c3a9ac247b688657337f5981efcfcb240dc
- https://git.kernel.org/stable/c/66339b71f105e6f83e0da3b9583d95077534fe1d
- https://git.kernel.org/stable/c/73963a375885d5ccb7def39fd0b4f542e0f343dd
- https://git.kernel.org/stable/c/84158c2997159df4a0d70cd9c46774512d32a522
- https://git.kernel.org/stable/c/eca989eab4b2599dcb02f72140a7c08f08838520