CVE-2025-62492Public exploit

One-element out-of-bounds read via rounded negative fromIndex

Published Oct 16, 2025 · Updated Oct 16, 2025

Out-of-bounds read in QuickJS 2025-04-26 allows attackers to probe one adjacent element via a tiny negative fromIndex value. In js_typed_array_indexOf, floating-point addition can round the negative value plus the array length to exactly that length, so the search starts beyond the valid buffer. An embedding application must execute crafted JavaScript; repeated equality probes expose at most the single element immediately following the buffer.

CVSS severity5.9
Medium
EPSS probability0.39%
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 read in QuickJS 2025-04-26 allows attackers to probe one adjacent element via a tiny negative fromIndex value. In js_typed_array_indexOf, floating-point addition can round the negative value plus the array length to exactly that length, so the search starts beyond the valid buffer. An embedding application must execute crafted JavaScript; repeated equality probes expose at most the single element immediately following the buffer.

The record

CVE
CVE-2025-62492
Published
Oct 16, 2025
Updated
Oct 16, 2025
Vendor
Fabrice Bellard
Product
QuickJS
Classifications
CWE-125, CAPEC-175
Attack vector
adjacent
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 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=2025-04-26 <2025-09-13

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesUnavailable in this record.

What is affected?

Fabrice Bellard · QuickJSversion=2025-04-26 <2025-09-13

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9Google Inc.CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L

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)
Vectoradjacent
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CAPEC-175Code Inclusion

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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