CVE-2026-12481: Keras Lambda Deserialization Can Bypass Safe Vulnerability

HIGH
Advisory Identifier: GHSA-5gwj-m78q-7pq3
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CVSS 8.8
CWE-502
Published
Advisory Summary

CVE-2026-12481 is a HIGH (CVSS 8.8) lambda deserialization can bypass safe vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Keras libraries in the PyPI ecosystem. The issue involves lambda deserialization can bypass safe mode and execute code. Remediation is available by upgrading affected packages to version 3.12.3, 3.15.0.

CVE-2026-12481 at a Glance

CVE Identifier CVE-2026-12481
GHSA Identifier GHSA-5gwj-m78q-7pq3
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Keras
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

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

How to Fix CVE-2026-12481

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

keras fixed: 3.12.3 
pip install keras>=3.12.3
keras fixed: 3.15.0 
pip install keras>=3.15.0
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 keras

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-12481, inspect your installed packages using pip:

pip show keras

Analyze the terminal output to locate any version of Keras in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.12.3), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Keras, 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 in keras-team/keras version 3.14.0 allows for arbitrary code execution due to improper handling of deserialization in the `Lambda` layer. Specifically, the `_raise_for_lambda_deserialization()` function fails to enforce the safe-mode guard when `safe_mode` is set to `None`, which is the default value when `from_config()` is called outside of a `SafeModeScope` context. This logic error conflates `None` (unset/default-deny) with `False` (explicitly disabled), bypassing the guard and allowing attacker-controlled `marshal` bytecode to be deserialized. Affected call sites include `keras.layers.deserialize(config)`, `keras.models.clone_model(model)`, and any direct invocation of `Lambda.from_config(config)` without an enclosing `SafeModeScope(True)`. This vulnerability can be exploited to achieve arbitrary OS-level code execution in the context of the server or user process.

CVE-2026-12481 Affected Keras Versions

2 component(s)
Fixed Versions:
3.12.33.15.0
Product / Package Ecosystem Affected Versions Fixed Version
keras
pypi/keras
PyPI
< 3.12.3
3.12.3
keras
pypi/keras
PyPI
≥ 3.13.0
< 3.15.0
3.15.0

References

NVD — CVE-2026-12481 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12481
Keras Source Repository REPOSITORY
https://github.com/keras-team/keras/pull/23048
Keras Source Repository REPOSITORY
https://github.com/keras-team/keras/pull/23165
Security Fix Commit FIX COMMIT
https://github.com/keras-team/keras/commit/55888d3becbdbb45dc16a55b489900f911e2dde5
Security Fix Commit FIX COMMIT
https://github.com/keras-team/keras/commit/d338a45204bdc787c8b3c4a9b82c1911cd52dedf
Keras Source Repository REPOSITORY
https://github.com/keras-team/keras
Keras Release RELEASE
https://github.com/keras-team/keras/releases/tag/v3.12.3
Keras Release RELEASE
https://github.com/keras-team/keras/releases/tag/v3.15.0
huntr.com/bounties/59ceaed1-c... WEB
https://huntr.com/bounties/59ceaed1-c8a3-4135-8f94-169ade02823d

Frequently Asked Questions

What is CVE-2026-12481?
CVE-2026-12481 is a security vulnerability in Keras involving Lambda deserialization can bypass safe mode and execute code under CWE-502: Deserialization of Untrusted Data.
Which Keras versions are affected?
Affected versions include releases prior to 3.12.3, 3.15.0 across affected packages: keras.
What version fixes CVE-2026-12481?
Upgrading to 3.12.3, 3.15.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is keras affected?
Yes, keras is affected in releases prior to 3.12.3, 3.15.0. Upgrade your dependency to 3.12.3, 3.15.0 or later.
What is the CVSS score of CVE-2026-12481?
CVE-2026-12481 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-12481?
CVE-2026-12481 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2026-12481?
Run the dependency tree command: 'pip show keras'. 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 
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  "id" : "GHSA-5gwj-m78q-7pq3",
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  "published" : "2026-07-03T21:31:36Z",
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  "database_specific" : {
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    "nvd_published_at" : "2026-07-03T21:16:54Z"
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}