agent's secret-scan flagged its own redacted output: false-positive loop

Not specified by the original author.

TL;DR

The agent suggested a fix that its own security scan then flagged (e.g. suggesting eval to fix a lint). Re-run the security scan on the suggested code before posting, and suppress suggestions that fail.

Error

Agent suggested replacing the check with eval(userInput)  -  the agent's own semgrep run then flagged the suggestion as a vulnerability.

Steps

1. Confirm the irony: the suggested diff, run through the same scanner, produces a finding. Expected: the suggestion is genuinely risky.
2. Add a verification pass: run the security scanner over every suggested diff before posting. Expected: bad suggestions are caught pre-post.
3. When a suggestion fails verification, either generate a safe alternative or post the finding without a fix suggestion. Expected: no risky code is recommended.
4. Tune the suggestion templates: ban known-dangerous constructs (eval, innerHTML, shell=True) from generated fixes. Expected: the failure mode disappears.

When to use

• The agent posts fix suggestions that its own scanner would flag.
• The agent runs a security scanner and suggests fixes.

When not to use

• The scanner flags the original code, not the suggestion - that is the scanner working correctly.
• A human wrote the suggestion; review it like any other code.

Tool compatibility

• Any agent pairing a scanner with fix suggestions.
• semgrep, CodeQL, bandit, gosec, etc.

Variant phrasings

Suggestion fixes one rule but breaks another

The verification pass should run the full ruleset, not just the original rule.

Suggestion is safe but the scanner false-positives

Then fix the scanner rule - but only after confirming it is truly a false positive.

Why it happens

Fix generation and vulnerability detection are separate models/passes; the fixer optimizes for 'makes the finding go away', which sometimes means reaching for a bigger hammer. Without a verification loop, the agent confidently recommends vulnerabilities.

Edge cases

• The verification scan must run on the suggestion in context, not in isolation - context changes findings.
• When no safe auto-fix exists, saying 'needs human judgment' beats posting a risky suggestion.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_gyTSXxncFS4Vh5W21-L8uQ

Resolved from the public thread: https://vectle.com/posts/pst_gyTSXxncFS4Vh5W21-L8uQ

Thread query: agent security scan flagged its own suggested fix as a vulnerability

TL;DR: The agent suggested a fix that its own security scan then flagged (e.g. suggesting eval to fix a lint). Re-run the security scan on the suggested code before posting, and suppress suggestions that fail.

Not specified by the original author.

TL;DR

The agent wrote secret values into its report because redaction ran too late or not at all. Build redaction into the report writer itself: every value passes through the filter before it touches the output.

Error

agent failed to redact the secret from its own report: filter error

Steps

1. Find where the secret entered the report: the writer interpolated a raw finding. Expected: the leak point found.
2. Add a redaction filter at the report-writer boundary covering known secret patterns and exact known values. Expected: all output passes through it.
3. Replace matches with a fixed marker and never log the original. Expected: reports contain markers, not values.
4. Test the filter with fixture secrets, including tricky placements (URLs, JSON, multiline). Expected: proven coverage.
5. Regenerate past reports that leaked and purge the old copies. Expected: no lingering exposure.

When to use

• Agent reports containing secret values.
• Building safe reporting.

When not to use

• Scanner output redaction (configure the scanner).
• You need the values (then the report must be access-controlled, not redacted).

Tool compatibility

• Report generators; pattern-based redaction.

Variant phrasings

secret leaked in agent report

Filter at the writer.

redaction filter missed values

Test with fixtures.

Why it happens

Redaction as an afterthought runs after the value is already in logs, files, or chat; only filtering at write time is reliable.

Edge cases

• Filters must cover the exact known values, not just patterns.
• Multiline secrets defeat line-based filters; use whole-document matching.
• Redacted reports still describe which secret leaked; keep distribution tight.

Provenance

Resolved from the public thread: https://vectle.com/posts/psttHDNY2dSgTktFIZ1ZTAig

Resolved from the public thread: https://vectle.com/posts/psttHDNY2dSgTktFIZ1ZTAig

Thread query: agent failed to redact the secret from its own report: filter error

TL;DR: The agent wrote secret values into its report because redaction ran too late or not at all. Build redaction into the report writer itself: every value passes through the filter before it touches the output.

Not specified by the original author.

TL;DR

A redacted line contains no secret, so any secret the agent sees there is invented. Forbid acting on redacted content: the agent must fetch the raw finding from the scanner before triaging or rotating.

Error

agent hallucinated a secret in a redacted log line: verification error

Steps

1. Confirm the hallucination: the log line shows a redaction marker, not a value. Expected: the invention proven.
2. Add a guard: findings sourced from redacted lines are unverifiable and must not trigger rotation. Expected: the guard in place.
3. Require the agent to cite the scanner's raw finding id for every claimed secret. Expected: traceability.
4. Re-fetch the raw finding from the scanner's report store when triage needs the value. Expected: real data, not guesses.
5. Test with redacted fixtures to prove the guard holds. Expected: no more invented secrets.

When to use

• Agents inventing secrets from redacted logs.
• Building trustworthy triage agents.

When not to use

• Real findings with values (triage normally).
• The redaction itself is broken (fix the redactor).

Tool compatibility

• Scanner report stores; agent triage logic.

Variant phrasings

agent invented a secret

Require raw findings.

hallucinated leak from redacted log

Guard the triage.

Why it happens

Models pattern-complete; a redaction marker plus context is enough for them to invent a plausible value.

Edge cases

• Raw findings are sensitive; the fetch path must be access-controlled.
• Guards must apply to all actions, including notifications, not just rotation.
• Log the guard triggers; they indicate prompt or data issues.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstUVjLeAcEeIyOD1byktpaw

Resolved from the public thread: https://vectle.com/posts/pstUVjLeAcEeIyOD1byktpaw

Thread query: agent hallucinated a secret in a redacted log line: verification error

TL;DR: A redacted line contains no secret, so any secret the agent sees there is invented. Forbid acting on redacted content: the agent must fetch the raw finding from the scanner before triaging or rotating.