Release Notes for [release-2026-08-20_03-30-base](https://github.com/dfinity/ic/tree/release-2026-08-20_03-30-base) (`79c01052b5f7f49d3cf53d04d696cb2893294cd3`)
This release is based on changes since [release-2026-08-13_03-55-base](https://dashboard.internetcomputer.org/release/59c42492cd6ee3ef5e60cd35d7b766e7bfd085da) (`59c42492cd6ee3ef5e60cd35d7b766e7bfd085da`).

Please note that some commits may be excluded from this release if they're not relevant, or not modifying the GuestOS 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-2026-08-13_03-55-base...release-2026-08-20_03-30-base).
## Features:
* [`d54472dd1`](https://github.com/dfinity/ic/commit/d54472dd1) Core Protocol: ic0_subnet_self_node_count ([#11132](https://github.com/dfinity/ic/pull/11132))
* [`0e0f48361`](https://github.com/dfinity/ic/commit/0e0f48361) Core Protocol: Add replicated state metric for the total value of pending anonymous refunds ([#11170](https://github.com/dfinity/ic/pull/11170))
* [`826017d58`](https://github.com/dfinity/ic/commit/826017d58) Core Protocol: make `canister_info` a query method of the management canister ([#11154](https://github.com/dfinity/ic/pull/11154))
* [`f48a8ce8d`](https://github.com/dfinity/ic/commit/f48a8ce8d) Core Protocol: Delete canister directory via `UnflushedCheckpointOp::DeleteCanister` ([#11158](https://github.com/dfinity/ic/pull/11158))
* [`655cdf32c`](https://github.com/dfinity/ic/commit/655cdf32c) Core Protocol: Add replicated state metrics for ingress history, queues, call contexts and refunds ([#11010](https://github.com/dfinity/ic/pull/11010))
* [`805c3af86`](https://github.com/dfinity/ic/commit/805c3af86) Core Protocol: Async HTTP outcalls refunds ([#11113](https://github.com/dfinity/ic/pull/11113))
* [`f227e5c95`](https://github.com/dfinity/ic/commit/f227e5c95) Core Protocol: Do not route canister messages to a cooling down subnet ([#11129](https://github.com/dfinity/ic/pull/11129))
* [`6ca30003d`](https://github.com/dfinity/ic/commit/6ca30003d) Core Protocol: migrate to ic-cdk 0.20 ([#11069](https://github.com/dfinity/ic/pull/11069))
* [`f84327316`](https://github.com/dfinity/ic/commit/f84327316) Core Protocol: Respect query limits from the registry ([#11111](https://github.com/dfinity/ic/pull/11111))
* [`27004e0d4`](https://github.com/dfinity/ic/commit/27004e0d4) Core Protocol: Lazy hashing of canister modules ([#11133](https://github.com/dfinity/ic/pull/11133))
* [`22f461c96`](https://github.com/dfinity/ic/commit/22f461c96) Core Protocol: Cap the amount of cycles that move into the per-replica HTTP outcalls allowance ([#11012](https://github.com/dfinity/ic/pull/11012))
* [`43d77537c`](https://github.com/dfinity/ic/commit/43d77537c) Core Protocol: Add a `version_id` field to `ReplicaVersionRecords` ([#10942](https://github.com/dfinity/ic/pull/10942))
* [`9e5a134a9`](https://github.com/dfinity/ic/commit/9e5a134a9) Core Protocol: Non-flexible out of cycles error ([#11085](https://github.com/dfinity/ic/pull/11085))
* [`ec265894e`](https://github.com/dfinity/ic/commit/ec265894e) Node: use pure-Rust libsystemd crate ([#11163](https://github.com/dfinity/ic/pull/11163))
## Bugfixes:
* [`59892f8e3`](https://github.com/dfinity/ic/commit/59892f8e3) Core Protocol: Consider reject responses when estimating new HTTP outcalls cost ([#11161](https://github.com/dfinity/ic/pull/11161))
* [`fbfb8dbeb`](https://github.com/dfinity/ic/commit/fbfb8dbeb) Core Protocol: validate the Wasm memory in create_execution_state ([#11168](https://github.com/dfinity/ic/pull/11168))
* [`440ca1dab`](https://github.com/dfinity/ic/commit/440ca1dab) Core Protocol: tolerate a cycles balance increase on DTS resume ([#11141](https://github.com/dfinity/ic/pull/11141))
* [`2c2e64d2d`](https://github.com/dfinity/ic/commit/2c2e64d2d) Core Protocol: account for install_code debit when loading a canister snapshot ([#11152](https://github.com/dfinity/ic/pull/11152))
* [`44ae9a3f1`](https://github.com/dfinity/ic/commit/44ae9a3f1) Core Protocol(canister_logging): reject a log_memory_limit below one page ([#11155](https://github.com/dfinity/ic/pull/11155))
* [`1cad024f2`](https://github.com/dfinity/ic/commit/1cad024f2) Core Protocol: dynamic HTTP outcalls per-replica cycles limit ([#11143](https://github.com/dfinity/ic/pull/11143))
* [`e1a7d3a6e`](https://github.com/dfinity/ic/commit/e1a7d3a6e) Core Protocol: CanisterDidNotReply for failed calls in composite queries ([#11104](https://github.com/dfinity/ic/pull/11104))
* [`a87fac145`](https://github.com/dfinity/ic/commit/a87fac145) Core Protocol: check the cycles balance and charge executed instructions on DTS resume ([#11039](https://github.com/dfinity/ic/pull/11039))
* [`95c917e23`](https://github.com/dfinity/ic/commit/95c917e23) Node: drop second arg in selinux policy ([#11147](https://github.com/dfinity/ic/pull/11147))
## Performance improvements:
* [`54e87a08f`](https://github.com/dfinity/ic/commit/54e87a08f) Core Protocol: Correct limit of derivation path length ([#11192](https://github.com/dfinity/ic/pull/11192))
* [`6f848ae87`](https://github.com/dfinity/ic/commit/6f848ae87) Core Protocol(key-manager): optimize some clones ([#11131](https://github.com/dfinity/ic/pull/11131))
## Chores:
* [`42b6c141d`](https://github.com/dfinity/ic/commit/42b6c141d) Core Protocol: Even better error messages for invalid keys ([#11198](https://github.com/dfinity/ic/pull/11198))
* [`2c31ebb0e`](https://github.com/dfinity/ic/commit/2c31ebb0e) Core Protocol(idkg): update ID generator's height together with the transcripts' references ([#11156](https://github.com/dfinity/ic/pull/11156))
* [`71e81592e`](https://github.com/dfinity/ic/commit/71e81592e) Core Protocol: simplify memory retrieval on upgrade and clarify preserving the memories on upgrade ([#11157](https://github.com/dfinity/ic/pull/11157))
* [`ce4b27fb0`](https://github.com/dfinity/ic/commit/ce4b27fb0) Core Protocol: Manually implement serde for `Cycles` and CBOR ([#11148](https://github.com/dfinity/ic/pull/11148))
* [`77aeae9c3`](https://github.com/dfinity/ic/commit/77aeae9c3) Core Protocol: Adjust instruction overhead ([#11146](https://github.com/dfinity/ic/pull/11146))
* [`cea9c9fde`](https://github.com/dfinity/ic/commit/cea9c9fde) Node: remove systemd from build container ([#11182](https://github.com/dfinity/ic/pull/11182))
* [`51ddfcf13`](https://github.com/dfinity/ic/commit/51ddfcf13) Node: Cleanup backup resizing ([#11137](https://github.com/dfinity/ic/pull/11137))
* [`eb5587356`](https://github.com/dfinity/ic/commit/eb5587356) Node: Small misc comment fixes ([#11106](https://github.com/dfinity/ic/pull/11106))
* [`6d2d6c6a7`](https://github.com/dfinity/ic/commit/6d2d6c6a7) Node: Use a tar lib instead of shelling out in fs build ([#11107](https://github.com/dfinity/ic/pull/11107))
* [`d04e42169`](https://github.com/dfinity/ic/commit/d04e42169) Node: Update Base Image Refs [2026-08-13-0830] ([#11125](https://github.com/dfinity/ic/pull/11125))
## Refactoring:
* [`484709584`](https://github.com/dfinity/ic/commit/484709584) Core Protocol: drop the legacy canister_log store from SystemState ([#10821](https://github.com/dfinity/ic/pull/10821))
* [`6bd6690d3`](https://github.com/dfinity/ic/commit/6bd6690d3) Core Protocol: install the canister memories in create_execution_state ([#11142](https://github.com/dfinity/ic/pull/11142))
* [`a3c4f796f`](https://github.com/dfinity/ic/commit/a3c4f796f) Core Protocol: snapshot memory size validation ([#11118](https://github.com/dfinity/ic/pull/11118))
## Tests:
* [`f8d5ae24c`](https://github.com/dfinity/ic/commit/f8d5ae24c) Core Protocol: Fix tests asserting on `ReplicatedStateMetrics` ([#11110](https://github.com/dfinity/ic/pull/11110))
## Other changes:
Full list of changes (including the ones that are not relevant to GuestOS) can be found on [GitHub](https://github.com/dfinity/dre/blob/816e0bd0465aefec6c02caf0a6b1811d470fab19/replica-releases/79c01052b5f7f49d3cf53d04d696cb2893294cd3.md).

# IC-OS Verification

To build and verify the IC-OS GuestOS 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/79c01052b5f7f49d3cf53d04d696cb2893294cd3/ci/scripts/repro-check | python3 - -c 79c01052b5f7f49d3cf53d04d696cb2893294cd3 --guestos
```

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 GuestOS version here, you have the option to verify the build reproducibility of the HostOS by passing `--hostos` to the script above instead of `--guestos`, or the SetupOS by passing `--setupos`.
