CVE-2025-6272: Pywasm3 Pywasm3 Has Improper Restriction Of Vulnerability

LOW
Advisory Identifier: GHSA-rrmw-gv85-w824
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CVSS 3.3
CWE-119
Published
Advisory Summary

CVE-2025-6272 is a LOW (CVSS 3.3) pywasm3 has improper restriction of vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting Pywasm3 libraries in the PyPI ecosystem. The issue involves pywasm3 has improper restriction of operations within the bounds of a memory buffer. Remediation is available in the latest vendor maintenance releases.

CVE-2025-6272 at a Glance

CVE Identifier CVE-2025-6272
GHSA Identifier GHSA-rrmw-gv85-w824
Severity LOW
CVSS v3.1 Base Score 3.3
CWE Classification CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
Affected Product Pywasm3
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 3.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2025-6272

To remediate this vulnerability, upgrade all affected Pywasm3 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pywasm3 fixed: Latest secure release 
pip install pywasm3>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pywasm3

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-6272, inspect your installed packages using pip:

pip show pywasm3

Analyze the terminal output to locate any version of Pywasm3 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show pywasm3 command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, where the product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. this may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. In Pywasm3, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability has been found in wasm3 0.5.0 and classified as problematic. This vulnerability affects the function MarkSlotAllocated of the file source/m3_compile.c. The manipulation leads to out-of-bounds write. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.

CVE-2025-6272 Affected Pywasm3 Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
pywasm3
pypi/pywasm3
PyPI
≤ 0.5.0

References

NVD — CVE-2025-6272 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-6272
Pywasm3 Source Repository REPOSITORY
https://github.com/wasm3/wasm3/issues/531
Pywasm3 Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pywasm3/PYSEC-2025-186.yaml
Pywasm3 Source Repository REPOSITORY
https://github.com/user-attachments/files/19516600/wasm3_crash.txt
Pywasm3 Source Repository REPOSITORY
https://github.com/wasm3/pywasm3
Pywasm3 Source Repository REPOSITORY
https://github.com/wasm3/pywasm3/blob/main/wasm3/m3_compile.c#L333
vuldb.com/ WEB
https://vuldb.com/?ctiid.313276
vuldb.com/ WEB
https://vuldb.com/?id.313276
vuldb.com/ WEB
https://vuldb.com/?submit.593008

Frequently Asked Questions

What is CVE-2025-6272?
CVE-2025-6272 is a security vulnerability in Pywasm3 involving pywasm3 has Improper Restriction of Operations within the Bounds of a Memory Buffer under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer.
Which Pywasm3 versions are affected?
Affected versions include releases prior to current release patches across affected packages: pywasm3.
What version fixes CVE-2025-6272?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is pywasm3 affected?
Yes, pywasm3 is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2025-6272?
CVE-2025-6272 has a CVSS v3.1 base score of 3.3 (LOW) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2025-6272?
CVE-2025-6272 is classified under CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer (The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.).
How can I check PyPI dependencies for CVE-2025-6272?
Run the dependency tree command: 'pip show pywasm3'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rrmw-gv85-w824",
  "modified" : "2026-06-09T19:09:31Z",
  "published" : "2025-06-19T18:31:47Z",
  "aliases" : [ "CVE-2025-6272" ],
  "summary" : "pywasm3 has Improper Restriction of Operations within the Bounds of a Memory Buffer",
  "details" : "A vulnerability has been found in wasm3 0.5.0 and classified as problematic. This vulnerability affects the function MarkSlotAllocated of the file source/m3_compile.c. The manipulation leads to out-of-bounds write. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS: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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pywasm3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-6272"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wasm3/wasm3/issues/531"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pywasm3/PYSEC-2025-186.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/user-attachments/files/19516600/wasm3_crash.txt"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/wasm3/pywasm3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wasm3/pywasm3/blob/main/wasm3/m3_compile.c#L333"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/?ctiid.313276"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/?id.313276"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/?submit.593008"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-119" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-09T19:09:31Z",
    "nvd_published_at" : "2025-06-19T18:15:22Z"
  }
}