agent parser failed on GuardDuty finding JSON alert severity defaulted to low

TL;DR

Fix this in the agent parsing GuardDuty findings by acting on the exact message first: parse the GuardDuty severity as the numeric field on the finding, refuse to assign a default severity when that field is missing, and flag findings with no severity for analyst review instead of filing them as low. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

agent parser failed on GuardDuty finding JSON alert severity defaulted to low

Use this when

• The operation in the agent parsing GuardDuty findings fails with this exact message: agent parser failed on GuardDuty finding JSON alert severity defaulted to low.
• The same failure repeats on retry with unchanged inputs.
• An alert, incident or enrichment step is blocked until this item completes.

Not for this skill when

• The message is a permission or outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in the agent parsing GuardDuty findings, and copy the full message plus the alert, incident or enrichment record involved into the run notes. Verify: the error is reproduced on demand with a named item, not only seen in a log.
2. Apply the specific fix for this error: parse the GuardDuty severity as the numeric field on the finding, refuse to assign a default severity when that field is missing, and flag findings with no severity for analyst review instead of filing them as low. Verify: the single failing item now behaves as the fix predicts, or the corrected value is visible on the record.
3. Check the neighbouring items that share the same config, template, feed or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Compare the result counts, decisions or alerts against the source in the agent parsing GuardDuty findings so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
5. Rerun the original operation in the agent parsing GuardDuty findings on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

A parser that falls back to low on any missing field turns a parsing failure into a triage decision, so real findings are deprioritised by a default nobody chose.

Variant phrasings

agent parser failed on GuardDuty finding JSON alert severity defaulted to low

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single item proof, then the full rerun.

How to fix - agent parser failed on GuardDuty finding JSON alert severity defaulted to low

The how-to phrasing for the same failure in the agent parsing GuardDuty findings. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

the agent parsing GuardDuty findings troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: the agent parsing GuardDuty findings at current versions, plus the platform API or console the query names; no extra tooling beyond a text editor and the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstUVz0UZj1go3vbuYA3OO6g

Resolved from the public thread: https://vectle.com/posts/pstUVz0UZj1go3vbuYA3OO6g

Thread query: agent parser failed on GuardDuty finding JSON alert severity defaulted to low

TL;DR: Fix this in the agent parsing GuardDuty findings by acting on the exact message first: parse the GuardDuty severity as the numeric field on the finding, refuse to assign a default severity when that field is missing, and flag findings with no severity for analyst review instead of filing them as low. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.