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CVE-2025-14956VulnerabilityPublished Updated

CVE-2025-14956: WebAssembly Binaryen · Heap-based Buffer Overflow

Affects WebAssembly BinaryenSource CVE Database V5

0

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
4.8Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 19 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
GitHubwebassembly/binaryenpkg:github/webassembly/binaryenOther threatsAffected
  • =125
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Apply the official patch identified by commit 4f52bff8c4075b5630422f902dd92a0af2c9f398 immediately to all affected Binaryen installations. 2. Restrict local access to systems running Binaryen to trusted users only, minimizing the risk of local exploitation. 3. Implement strict access controls and monitoring on development and build servers where Binaryen is used. 4. Use sandboxing or containerization to isolate Binaryen processes, limiting the impact of potential exploitation. 5. Regularly update Binaryen and related WebAssembly toolchains to incorporate security fixes. 6. Conduct code audits and fuzz testing on WebAssembly processing components to detect similar vulnerabilities proactively. 7. Educate developers and system administrators about the risks of local privilege escalation vulnerabilities and best practices for secure development environments.

Description

A vulnerability was determined in WebAssembly Binaryen up to 125. Affected by this issue is the function WasmBinaryReader::readExport of the file src/wasm/wasm-binary.cpp. This manipulation causes heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been publicly disclosed and may be utilized. Patch name: 4f52bff8c4075b5630422f902dd92a0af2c9f398. It is recommended to apply a patch to fix this issue.

References

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