CVE-2025-57632Public exploitNetwork attack vector

Client crash via chained PDU iovec overflow

Published Sep 25, 2025 · Updated Sep 25, 2025

Buffer overflow in libsmb2 6.2 and later allows remote attackers controlling an SMB server to crash a connecting client via chained PDUs. smb2_add_iovector() increments v->niov and writes another entry into the fixed 256-element iovec array without checking its upper bound. A client must connect to a malicious SMB server; SMB2_OPLOCK_BREAK responses bypass message-ID matching and permit enough chained entries to corrupt heap memory and interrupt the client process.

CVSS severity7.5
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in libsmb2 6.2 and later allows remote attackers controlling an SMB server to crash a connecting client via chained PDUs. smb2_add_iovector() increments v->niov and writes another entry into the fixed 256-element iovec array without checking its upper bound. A client must connect to a malicious SMB server; SMB2_OPLOCK_BREAK responses bypass message-ID matching and permit enough chained entries to corrupt heap memory and interrupt the client process.

The record

CVE
CVE-2025-57632
Published
Sep 25, 2025
Updated
Sep 25, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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