[AutoPR- Security] Patch rabbitmq-server for CVE-2026-43973 [MEDIUM]

[azurelinux-security]

Auto Patch rabbitmq-server for CVE-2026-43973.

Autosec pipeline run -> https://dev.azure.com/mariner-org/mariner/_build/results?buildId=1140800&view=results

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./LICENSES-AND-NOTICES/SPECS/data/licenses.json, ./LICENSES-AND-NOTICES/SPECS/LICENSES-MAP.md, ./LICENSES-AND-NOTICES/SPECS/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

What does the PR accomplish, why was it needed?

• Auto Patch rabbitmq-server for CVE-2026-43973 (MEDIUM).

Change Log

• CVE-2026-43973

Does this affect the toolchain?

YES/NO

Associated issues

• N/A

Links to CVEs

• https://nvd.nist.gov/vuln/detail/CVE-2026-43973

Test Methodology

• Pipeline build id: Buddy Build URL

[BinduSri-6522866]

CVE-2026-43973:

1. Manually backported patch because the existing Gun code does not keep "opts" in the same way as upstream.
2. So instead of reading the new limits directly from opts, added the fix to the older code structure by storing the new header/trailer size limits in state during initialization.
3. Added checks while reading headers and trailers so processing stops if they become too large.

Buddybuild: https://dev.azure.com/mariner-org/mariner/_build/results?buildId=1141628&view=results

[mayankfz]

Manual backport looks fine with some adaptations to the older version.
Buddy build passes.

[kgodara912]

Patch is backported from different version of upstream except documentation and test. Buddy build is successful. LGTM.