CVE-2025-13016Public exploitNetwork attack vector

Memory corruption via mis-sized WebAssembly array copy

Published Nov 11, 2025 · Updated Apr 13, 2026

Stack buffer overflow in Mozilla Firefox and Thunderbird before 145 and ESR before 140.5 allows remote attackers to corrupt memory. The StableWasmArrayObjectElements constructor gives std::copy a byte-counted source endpoint while copying typed elements, multiplying the copy length by the element size. A user must process attacker-controlled WebAssembly content; public proofs demonstrate incorrect data and a stack-buffer-overflow crash.

CVSS severity7.5
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in Mozilla Firefox and Thunderbird before 145 and ESR before 140.5 allows remote attackers to corrupt memory. The StableWasmArrayObjectElements constructor gives std::copy a byte-counted source endpoint while copying typed elements, multiplying the copy length by the element size. A user must process attacker-controlled WebAssembly content; public proofs demonstrate incorrect data and a stack-buffer-overflow crash.

The record

CVE
CVE-2025-13016
Published
Nov 11, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-703, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record 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

7.5CISA ADP VulnrichmentCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-703Improper Check or Handling of Exceptional Conditions
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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