CVE-2026-53246: Linux Kernel buffer overflow (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing When a listening SCTP server processes a COOKIE_ECHO chunk, the cached peer INIT chunk embedded after the cookie is parsed and its parameters are later walked by sctp_process_init() using sctp_walk_params(). However, the chunk header length of this cached INIT chunk was not validated against the remaining buffer in the COOKIE_ECHO payload. If the length field is inflated, the parameter walk can run beyond the actual received data, leading to out-of-bounds reads and potential memory corruption during later parameter handling (e.g. STATE_COOKIE processing and kmemdup() copies). Add a bounds check in sctp_unpack_cookie() to ensure the cached INIT chunk length does not exceed the available data in the COOKIE_ECHO buffer before it is used.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 2.6.12.1 < 6.18.36 · ≥ 6.19 < 7.0.13 · 2.6.12 · 7.1

Remediation

Fixed in

Linux Kernel≥ 6.18.36

Patch & vendor advisories

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-53246 being actively exploited?

CVE-2026-53246 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.44%.

How severe is CVE-2026-53246?

CVE-2026-53246 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.44% probability of exploitation.

Which products are affected by CVE-2026-53246?

Affected products include Linux Kernel.

How do I fix CVE-2026-53246?

Upgrade affected software to a fixed version, for example Linux Kernel 6.18.36 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-53246 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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