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CVE-2025-39946

CRITICAL
9.8
CVSS 3.1
Description
In the Linux kernel, the following vulnerability has been resolved: tls: make sure to abort the stream if headers are bogus Normally we wait for the socket to buffer up the whole record before we service it. If the socket has a tiny buffer, however, we read out the data sooner, to prevent connection stalls. Make sure that we abort the connection when we find out late that the record is actually invalid. Retrying the parsing is fine in itself but since we copy some more data each time before we parse we can overflow the allocated skb space. Constructing a scenario in which we're under pressure without enough data in the socket to parse the length upfront is quite hard. syzbot figured out a way to do this by serving us the header in small OOB sends, and then filling in the recvbuf with a large normal send. Make sure that tls_rx_msg_size() aborts strp, if we reach an invalid record there's really no way to recover.

Metadata

CVE ID
CVE-2025-39946
State
PUBLISHED
Assigner
Linux
Reserved
2025-04-16 07:20 UTC
Published
2025-10-04 07:31 UTC
Last updated
2026-06-16 16:11 UTC
Vendor / Product
Linux / Linux
Sources
cve.org  ·  NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
none
Automatable
yes
Tech. Impact
total
Affected products (2)
VendorProductPlatformVersions
Linux Linux 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < b36462146d86b1f22e594fe4dae611dffacfb203, 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 4cefe5be73886f383639fe0850bb72d5b568a7b9, 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 208640e6225cc929a05adbf79d1df558add3e231, 84c61fe1a75b4255df1e1e7c054c9e6d048da417 < 61ca2da5fb8f433ce8bbd1657c84a86272133e6b …
Linux Linux 6.0, 0 < 6.0, 6.1.154 ≤ 6.1.*, 6.6.108 ≤ 6.6.* …
CVSS scores (1)
ScoreSeverityVersionSourceVector
9.8 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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