Cherry-pick #18311 to 3.0-dev: Patch keras for CVE-2026-12480 (supersedes #17925 revert)

[jslobodzian]

[Toolio Iglesias🗺️] Cherry-picking PR #18311 from fasttrack/3.0 to bring the CVE-2026-12480 keras patch back into 3.0-dev.

Why this is safe now (unlike #17925)

PR #17925 originally patched CVE-2026-12480 on 3.0-dev on 2026-07-13 and was reverted by #18286 on 2026-08-01 because it broke the AMD64 DEV golden container Test tensorflow phase with:

ImportError: cannot import name 'h5py' from 'keras.src.utils.module_utils'

Root cause: #17925 added from keras.src.utils.module_utils import h5py at the top of keras/src/saving/saving_lib.py, but never declared h5py inside module_utils.py. That symbol only existed if the underlying h5py package was importable, and the tensorflow container's .pipelines/containerSourceData/tensorflow/tensorflow.pkg doesn't request python3-h5py — so every import tensorflow blew up.

What's different in #18311

PR #18311 is the actual upstream keras fix (keras-team/keras#22801 by hertschuh), not the AllSpark AI-generated backport used in #17925. It touches a third file — keras/src/utils/module_utils.py:

 scipy = LazyModule("scipy")
 jax = LazyModule("jax")
+h5py = LazyModule("h5py")
 optree = LazyModule("optree")

LazyModule resolves the real package only when a method/attribute is accessed, so import tf.keras succeeds even in containers that don't have python3-h5py installed. No new package deps required.

Validation

• The fix landed on fasttrack/3.0 on 2026-08-07 as PR [Medium] Patch keras for CVE-2026-12480 #18311.
• Downstream Golden Container tests on 2026-08-11 (builds 1180168 AMD64 / 1180041 ARM64) succeeded, with Test tensorflow phase = succeeded on both arches.
• Container SBOM confirms python3-keras-3.3.3-8.azl3 + python3-h5py-3.10.0-2.azl3 installed cleanly from PMC.

Refs

• Original CVE PR (fasttrack): [Medium] Patch keras for CVE-2026-12480 #18311
• Revert PR that this supersedes: Revert "[AutoPR- Security] Patch keras for CVE-2026-12480 [MEDIUM] (#17925)" — breaks tensorflow golden container #18286
• Earlier broken backport: [AutoPR- Security] Patch keras for CVE-2026-12480 [MEDIUM] #17925
• Upstream keras fix: keras-team/keras#22801