DFINITY Foundation

ICDevs.org

CryptoIsGood

Anvil

ICPL.app

ysyms

The Accumulators’ Neuron

RawTech Venture

Paul Young

ICPMANUAL

8YearGangDAO

Isaac Valadez

Krzysztof

Nicolas.ic

Smaug’s Neuron for Retail Investors

ICLight.io

Taggr Network

Sonic AMM

Rakeoff.io

OpenChat

ELNA AI

GEEKFACTORY

ICP Hub México

ICP Hub Poland

Jerry Banfield

WaterNeuron

ICP Hub Bulgaria

Gold DAO

NeuronPool

LORIMER ♾️ 🐶

B3Pay

ZenithCode

Aviate Labs

D-QUORUM

Yuku AI

CO.DELTA △

DragginCorp

Gwojda

Thyassa

🌮 TACO DAO Neuron

Ωmega-reject

Ωmega-vote

αlpha-vote

Cybersecurity

cyberowl

Dexter Caff/acc

JMVR

Smacker

HashEra

Change the set of currently elected HostOS versions, by electing a new version, and/or unelecting some priorly elected versions.

HostOS versions are identified by the hash of the installation image.

The version to elect is added to the Registry, and the versions to unelect are removed from the Registry, ensuring that HostOS cannot upgrade to these versions anymore.

This proposal does not actually perform the upgrade; for deployment of an elected version, please refer to "Deploy HostOS To Some Nodes".

Release Notes for [**release-2026-08-27\_05-01-base**](https://github.com/dfinity/ic/tree/release-2026-08-27_05-01-base) (e9fd136f3fed6cb44625379e056ad63789d52d2c)
===================================================================================================================================================================

This release is based on changes since [release-2026-08-20\_03-30-base](https://dashboard.internetcomputer.org/release/79c01052b5f7f49d3cf53d04d696cb2893294cd3) (79c01052b5f7f49d3cf53d04d696cb2893294cd3).

Please note that some commits may be excluded from this release if they're not relevant, or not modifying the HostOS image. Additionally, descriptions of some changes might have been slightly modified to fit the release notes format.

To see a full list of commits added since last release, compare the revisions on [GitHub](https://github.com/dfinity/ic/compare/release-2026-08-20_03-30-base...release-2026-08-27_05-01-base).

Features:
---------

* [`5101fcedb`](https://github.com/dfinity/ic/commit/5101fcedb) Node: Implement new bazel rules for building SEV recovery GuestOS images ([#10571](https://github.com/dfinity/ic/pull/10571))
* [`0199d9aea`](https://github.com/dfinity/ic/commit/0199d9aea) Node: Restructure VSOCK code as a starting point for improvements ([#11247](https://github.com/dfinity/ic/pull/11247))

Bugfixes:
---------

* [`1f89cb871`](https://github.com/dfinity/ic/commit/1f89cb871) Core Protocol,Node: enable mld listener queries, disable multicast snooping ([#11246](https://github.com/dfinity/ic/pull/11246))

Chores:
-------

* [`a08ba3203`](https://github.com/dfinity/ic/commit/a08ba3203) Node: Cleanup Type 4.0 deployment path ([#11207](https://github.com/dfinity/ic/pull/11207))
* [`65ec331c2`](https://github.com/dfinity/ic/commit/65ec331c2) Node: Update Base Image Refs [2026-08-20-0811] ([#11229](https://github.com/dfinity/ic/pull/11229))

------------------------------------------
Full list of changes (including the ones that are not relevant to HostOS) can be found on [GitHub](https://github.com/dfinity/dre/blob/619ad7ca0a8bec2419dac03fd66565cd51fbeaba/hostos-releases/e9fd136f3fed6cb44625379e056ad63789d52d2c.md).

# IC-OS Verification

To build and verify the IC-OS HostOS disk image, after installing curl if necessary (`sudo apt install curl`), run:

```
# From https://github.com/dfinity/ic#verifying-releases
curl -fsSL https://raw.githubusercontent.com/dfinity/ic/e9fd136f3fed6cb44625379e056ad63789d52d2c/ci/scripts/repro-check | python3 - -c e9fd136f3fed6cb44625379e056ad63789d52d2c --hostos
```

The two SHA256 sums printed above from a) the downloaded CDN image and b) the locally built image, must be identical, and must match the SHA256 from the payload of the NNS proposal.

While not required for this NNS proposal, as we are only electing a new HostOS version here, you have the option to verify the build reproducibility of the GuestOS by passing `--guestos` to the script above instead of `--hostos`, or the SetupOS by passing `--setupos`.


Elect new IC/HostOS revision (commit e9fd136)