diff --git a/.agents/skills/release-notes/SKILL.md b/.agents/skills/release-notes/SKILL.md
index a6f6c8a8c..f2afc0076 100644
--- a/.agents/skills/release-notes/SKILL.md
+++ b/.agents/skills/release-notes/SKILL.md
@@ -20,6 +20,7 @@ Use this skill when:
 Ask the user for:
 1. **New version number** (e.g., `v2.5.0`)
 2. **Release date** (default: today)
+3. **Release branch** (optional): The branch from which the release will be cut. Defaults to `HEAD`. When the release is cut from a different branch (e.g., `release-2.0`), use that branch as the upper bound of the commit range instead of `HEAD`. Release notes may be written on `main` even though the release is cut from a release branch.
 
 Then determine the previous release tag automatically:
 ```bash
@@ -28,25 +29,25 @@ git tag --sort=-v:refname | head -1
 
 ## Step 2: Collect Git History
 
-Run these commands to gather the raw data (replace `<prev>` with the previous tag):
+Run these commands to gather the raw data. Replace `<prev>` with the previous tag and `<release>` with the release branch (e.g., `upstream/release-2.0`) or `HEAD` if releasing from the current branch:
 
 ```bash
 # Full commit log
-git log <prev>..HEAD --oneline
+git log <prev>..<release> --oneline
 
 # Contributors with commit counts
-git shortlog -sne <prev>..HEAD
+git shortlog -sne <prev>..<release>
 
 # New controller directories (compare directory listings)
 diff <(git ls-tree -d --name-only <prev> internal/controllers/ | sort) \
-     <(git ls-tree -d --name-only HEAD internal/controllers/ | sort) \
+     <(git ls-tree -d --name-only <release> internal/controllers/ | sort) \
   | grep '^>'
 
 # All authors who ever contributed before this release
 git log <prev> --format='%aN' | sort -u > /tmp/old-contributors.txt
 
 # Authors in this release
-git log <prev>..HEAD --format='%aN' | sort -u > /tmp/new-contributors.txt
+git log <prev>..<release> --format='%aN' | sort -u > /tmp/new-contributors.txt
 
 # First-time contributors
 comm -13 /tmp/old-contributors.txt /tmp/new-contributors.txt
@@ -54,10 +55,12 @@ comm -13 /tmp/old-contributors.txt /tmp/new-contributors.txt
 
 For each first-time contributor, find the PR number of their first contribution:
 ```bash
-git log <prev>..HEAD --author="<name>" --oneline --reverse | head -1
+git log <prev>..<release> --author="<name>" --oneline --reverse | head -1
 ```
 Then look up the corresponding PR number from the merge commit message (format: `Merge pull request #NNN`).
 
+> **Note**: When using a release branch, make sure to fetch it first (e.g., `git fetch upstream release-2.0`). The merge commit on the release branch may reference a backport PR number rather than the original PR. Use the original PR number from `main` for release notes since that's where the review and discussion happened.
+
 ## Step 3: Categorize Changes
 
 Review every commit and sort into sections. Use these rules:
diff --git a/website/docs/changelog.md b/website/docs/changelog.md
index f1f0c985f..ed9a49857 100644
--- a/website/docs/changelog.md
+++ b/website/docs/changelog.md
@@ -1,5 +1,26 @@
 # Changelog
 
+## v2.6 - June 10, 2026
+
+### New features
+
+- Flavor: Added `id` field for creation
+
+### Bug fixes
+
+- Tightened adoption filters across multiple controllers (AddressScope, FloatingIP, Group, Network, Port, Project, Router, SecurityGroup, ServerGroup, Subnet, Trunk, User) to prevent adopting resources that don't fully match the spec
+- Fixed terminal error classification: use `IsRetryable` instead of `IsConflict` so non-HTTP gophercloud errors (e.g., client-side validation failures) are no longer retried indefinitely (Fixes [#241](https://github.com/k-orc/openstack-resource-controller/issues/241))
+- Treated Neutron quota-exceeded 409 errors as retryable so controllers retry when quota becomes available (Fixes [#667](https://github.com/k-orc/openstack-resource-controller/issues/667))
+- Fixed port status not updating to ACTIVE after server interface attachment
+- Fixed volume status not updating to in-use after server attachment
+
+### Infrastructure improvements
+
+- Bumped Go to 1.25.11
+- Bumped kuttl to v0.26.0
+- Bumped golang.org/x/net to v0.53.0 and other dependency updates
+- Added CI verification for `generate-bundle`
+
 ## v2.5 - April 16, 2026
 
 This release adds five new controllers spanning Neutron and Keystone services,