CVE-2026-43185 (GCVE-0-2026-43185)

Vulnerability from cvelistv5 – Published: 2026-05-06 11:27 – Updated: 2026-05-11 22:19
VLAI?
Title
ksmbd: fix signededness bug in smb_direct_prepare_negotiation()
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in smb_direct_prepare_negotiation() smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32)
Severity ?
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < ceae058eb707ddd0d68f0872f9d9f23b7c30c37b (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 55abc475d096da4a5356b6efb0cfdc6156bc1550 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 6b4f875aac344cdd52a1f34cc70ed2f874a65757 (git)
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Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.18.16 , ≤ 6.18.* (semver)
Unaffected: 6.19.6 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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