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TI-2026-74155 Aliases CVE-2026-110714GHSA-f7hf-m5cf-j6wv

Integer underflow in libsmb2 decode_acl causes heap over-read

Priority MEDIUM 64CWE-191Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-191 and the CVSS impact.

Summary

libsmb2 from sahlberg is affected through 6.2. An integer underflow in decode_acl (CWE-191) lets crafted security descriptors make the client read past heap buffers. A malicious SMB server, or an attacker intercepting unsigned sessions, can send an AclSize below 8 in a QUERY_INFO reply to crash the client. A public exploit is linked in the references.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00538 45th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sahlberglibsmb2up to 6.2—No fix listedCNA
  • libsmb2 Vendorsahlberg Affected up to 6.2 Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for libsmb2.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Timeline

  1. 2026-10-14 Threatist record created from CVE-2026-110714
  2. 2026-10-15 Alias added: GHSA-f7hf-m5cf-j6wv
  3. 2026-10-16 Priority changed: MEDIUM → LOW
  4. 2026-10-20 CISA SSVC decision points changed
  5. 2026-10-20 Priority changed: LOW → MEDIUM

References

Exploit 1

Patch 1

Other 2

  • TI-2026-79487 Integer overflow in libsmb2 DCE/RPC NDR decoder lets servers corrupt heap CVSS 4.0HIGH 7.2
  • TI-2026-74154 libsmb2 Heap Out-of-Bounds Read via File System Info Decoders CVSS 4.0HIGH 7.1
  • TI-2026-74153 Heap out-of-bounds read in libsmb2 lets SMB servers crash clients CVSS 4.0HIGH 7.1
  • TI-2026-41697 Integer underflow in sahlberg libnfs CVSS 3.1HIGH 7.1
  • TI-2026-38717 libnfs through 6.0.2 before 55c18ea does not validate a string size, leading to an… CVSS 3.1HIGH 7.1
  • TI-2026-70831 Out-of-bounds write in libnfs ZDR decoding CVSS 3.1HIGH 7.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences