CVE-2026-110714 json
libsmb2 through 6.2 Heap Out-of-Bounds Read via decode_acl Integer Underflow
published 2026-10-14 25 d ago modified 2026-10-20 20 d ago also EUVD-2026-101137
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
libsmb2 through 6.2 contains an integer underflow vulnerability in decode_acl that allows malicious SMB servers to trigger heap out-of-bounds reads via crafted security descriptors. Attackers controlling a server or intercepting unsigned sessions can send an AclSize below 8 in a QUERY_INFO reply, bypassing ACE bounds checks and crashing the client.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 20 d ago
Exploit prediction
0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- hackmd.io https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- sahlberg libsmb2
Classification
- Weakness
-
- CWE-191 Integer Underflow (Wrap or Wraparound)
References
-
github.com
/sahlberg/libsmb2/commit/523abe20be3207011a936db47f1d3bab79c05450
patch
-
hackmd.io
/@haind-pwn/libsmb2-query-info-reply-oob-read
technical-description, exploit
-
github.com
/sahlberg/libsmb2/blob/d67e213a5c4e7e4969fd81f0b95e4ca5831fbba1/lib/smb2-data-security-descriptor.c#L266
technical-description
-
github.com
/sahlberg/libsmb2
product
-
vulncheck.com
/advisories/libsmb2-through-6.2-heap-out-of-bounds-read-via-decode-acl-integer-underflow
third-party-advisory
Sources
- CVE List CVE-2026-110714
- NVD CVE-2026-110714
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.