CVE-2025-6272Public exploit

Local runtime crash via unchecked slot allocation

Published Jun 19, 2025 · Updated Jun 23, 2025

Out-of-bounds write in MarkSlotAllocated in Wasm3 0.5.0 allows local users to crash the runtime via a crafted WebAssembly module. MarkSlotAllocated writes to o->m3Slots[i_slot] without checking that the slot index remains within the fixed allocation table during CompileBlock. Exploitation requires local ability to make the runtime compile the supplied module, and the demonstrated consequence is a process crash.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in MarkSlotAllocated in Wasm3 0.5.0 allows local users to crash the runtime via a crafted WebAssembly module. MarkSlotAllocated writes to o->m3Slots[i_slot] without checking that the slot index remains within the fixed allocation table during CompileBlock. Exploitation requires local ability to make the runtime compile the supplied module, and the demonstrated consequence is a process crash.

The record

CVE
CVE-2025-6272
Published
Jun 19, 2025
Updated
Jun 23, 2025
Vendor
Wasm3 Labs
Product
Wasm3
Classifications
CWE-119, CWE-787, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Wasm3 Labs · Wasm3version=0.5.0

Published CVSS scores

4.8VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
3.3VulDBCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
3.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
1.7VulDBAV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

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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