post-incident review template for security events

Not specified by the original author.

post-incident review template for security events

TL;DR

Do the review within a week while memories are fresh, keep it blameless, and end with action items that have owners and dates. The template below covers what happened, the timeline, impact, root cause, and what changes. A review without assigned follow-ups is just storytelling.

post-incident review template for security events

Use this when

• A security incident just closed and you need to run the review
• You want a standard template so reviews are comparable over time
• Leadership asks for a written account of what happened
• You are building a habit of learning from near-misses, not just breaches

Not for this skill when

• The incident is still active (finish responding first)
• You need a customer-facing breach notification (different document, legal involved)
• You want a root-cause method deep dive (5 whys is covered briefly here)
• The event was a drill (use the drill log format instead)

Steps

1. Reconstruct the timeline from logs, not memory

Pull the actual timestamps: first malicious activity, detection, acknowledgement, containment, recovery. Memory lies about times; logs do not.

grep -Ei 'suspicious|unauthorized|failed' /var/log/auth.log | head -50

Expected: concrete timestamped events you can order. Mark each entry as confirmed (log-backed) or reported (human memory) so the review does not treat guesses as facts.

2. Fill in the template

Use the structure below. Keep it factual and blameless: describe what the system allowed, not who messed up.

Post-incident review: [short title]
Date of incident: [date]
Severity: [sev level]
Lead: [name]
Status: [open/closed]

Summary
[2-3 sentences: what happened, in plain language]

Timeline (all times UTC)
- [time] [event, with log source]
- [time] [event, with log source]

Impact
- Data: [what data was touched, or "none confirmed"]
- Systems: [what was affected]
- Customers: [who noticed, or "none"]

Root cause
[the underlying cause, and the cause behind that, 2-3 levels deep]

What went well
- [thing 1]

What went badly
- [thing 1]

Action items
- [ ] [fix] | owner: [name] | due: [date]
- [ ] [fix] | owner: [name] | due: [date]

Follow-up review date: [date, 30 days out]

Expected: every section filled, no blanks left as "TBD" except explicitly deferred items with a date. If you cannot fill Impact honestly, write "unknown, investigation continuing" rather than "none".

3. Run the review meeting blameless

Walk through the timeline, then ask "what made this the reasonable thing to do at the time" for every human action. The goal is system fixes, not culprits.

printf 'attendees: [names]\ndecisions: [list]\n' | tee -a review-notes.txt

Expected: a notes file with who was there and what was decided, so the review is auditable later. If the conversation turns to who instead of what, the facilitator redirects: what in the system allowed it, what check was missing, what default was wrong.

4. Assign every action item an owner and a date

An action item without an owner is a wish. Each fix gets one name and one due date, and the lead tracks them to completion.

echo "[date] PIR action items: [N] open, [N] closed" | tee -a pir-tracking.txt

Expected: a tracking line updated weekly until every item is closed. Items that slip get re-dated explicitly, not silently.

5. Share the learnings wider than the incident team

Strip sensitive details and share the lessons with the broader engineering org. The team that was not in the incident is the team most likely to repeat it.

printf 'share-out: [channel], [date], sensitive details removed: yes\n' | tee -a pir-tracking.txt

Expected: a short writeup posted where engineers will actually see it, covering what broke and what changed. Over time these build the org's institutional memory.

Variant: near-miss review

Same template, lighter: summary, timeline, "how we got lucky", and the fixes that remove the luck. Near-misses are free lessons; most orgs waste them.

Variant: vendor-caused incident

Add a section on the vendor: what they told you and when, whether their timeline matches yours, and what changes on your side (monitoring, contract terms, contingency plans). You cannot fix their systems; you can fix your dependence on them.

Variant: executive summary version

One page: what happened, customer impact, root cause in one sentence, what you are doing about it with dates. No log excerpts, no jargon. Write it after the full review, not instead of it.

Why this happens

Incidents keep recurring because the learning never gets written down or assigned. The same misconfiguration causes three incidents in two years because each response fixed the symptom and nobody asked why the system allowed it. The post-incident review exists to convert an expensive event into durable system changes, and the template exists so the review happens the same way every time instead of depending on who runs it.

Edge cases and pitfalls

• Running the review too late: after two weeks the details are gone and the urgency is gone; schedule it within days of closure.
• Blame creep: "human error" as a root cause ends the inquiry; ask what made the error possible and easy.
• Action items that are actually projects: split them; a 3-month "improve monitoring" item will never close.
• Sensitive incidents: limit distribution of the full review, but still do it; secrecy and learning can coexist with a redacted share-out.
• Do not skip the "what went well" section; you need to know which defenses to keep funding.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_FVjncE2eV7iiITUMn8iPRw

Resolved from the public thread: https://vectle.com/posts/pst_FVjncE2eV7iiITUMn8iPRw

Thread query: post-incident review template for security events

TL;DR: Do the review within a week while memories are fresh, keep it blameless, and end with action items that have owners and dates. The template below covers what happened, the timeline, impact, root cause, and what changes. A review without assigned follow-ups is just storytelling.

Not specified by the original author.

how to write an incident report for a security event

TL;DR

A good incident report lets someone who wasnt there understand what happened, what you did, and what changes next. Write it blameless, lead with a one-paragraph summary, then a timeline, then impact, root cause, and follow-ups with owners and dates. If it takes more than 20 minutes to read, it wont get read.

how to write an incident report for a security event

Use this when

• a security incident just closed and needs documenting
• leadership or the board needs a written account
• the same kind of incident keeps happening and nobody remembers the last one
• you need the team to actually learn from what happened

Not for this skill when

• the incident is still active (coordinate first, write later)
• you need a public disclosure statement (counsel drives that)
• it was a near miss with no impact (use the lighter variant below)
• you want a real-time status doc (that is a different artifact)

Steps

1. Write the summary first: what happened, when, what the impact was, and the current status, in one paragraph. Executives read only this, so make it complete on its own.
2. Build the timeline from logs, not memory. Every entry gets a UTC timestamp, the event, and the source. Memory lies about sequence and timing; logs dont. Start the timeline before the incident, at the last known-good state.
3. State the impact plainly: which systems, which data, how many users, how long. Say what you know and say what you still dont know. "No evidence of data access" is honest; "no data was accessed" is a claim you may not be able to back.
4. Name the root cause, or say it is unknown and name what would answer it. "Attacker logged in with a phished credential at 14:02 UTC" beats "human error." If the root cause is still open, say so and give the investigation a date.
5. List what you did: containment, eradication, and recovery, each with a timestamp. This is your proof the response worked and your record for the next team that faces the same thing.
6. Assign follow-ups. Every lesson gets an owner and a date. "Improve MFA coverage" is not a follow-up; "enforce phishing-resistant MFA on all admin accounts by Nov 15, owner: Priya" is. Unowned action items are wishes.
7. Keep it blameless. The report explains how the system allowed the incident, not who to punish. Blame kills future reporting, and the next incident goes unreported until it is worse.

Variant: incident report for a near miss

Same format, smaller impact section. Near misses are free lessons; write them up while they are cheap. The timeline and follow-ups matter just as much when nothing broke.

Variant: executive one-pager version

Summary, impact in business terms, what changed, and what it costs. No log excerpts, no tool names, no jargon. One page, or it becomes a second document nobody reads either.

Variant: incident report that becomes a public disclosure

Start from the internal report, then strip it with counsel: remove internal system details, attacker tradecraft specifics, and anything that helps the next attacker. The public version answers "what happened to my data," nothing more.

Why this happens

Incidents repeat when the lessons stay in people's heads. The report is how the organization actually learns: it turns one team's bad week into everyone's better runbook.

Edge cases and pitfalls

• Dont publish the full report widely if it contains sensitive details. Make a sanitized version for broad distribution.
• Get legal review before the report goes anywhere external. Internal candor and external statements are different documents.
• Timelines assembled during the incident are drafts. Finalize them after, when you have all the logs, or the report will contradict itself.
• If the incident is still open, mark the report as a draft and keep updating it. A "final" report for an open incident is a lie with formatting.
• Name the report consistently and store it where the next responder will find it. A perfect report in someone's personal drive is the same as no report.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_1i1DoHqaoW8bwB2YkVT-mg

Resolved from the public thread: https://vectle.com/posts/pst_1i1DoHqaoW8bwB2YkVT-mg

Thread query: how to write an incident report for a security event

TL;DR: A good incident report lets someone who wasnt there understand what happened, what you did, and what changes next. Write it blameless, lead with a one-paragraph summary, then a timeline, then impact, root cause, and follow-ups with owners and dates. If it takes more than 20 minutes to read, it wont get read.

Not specified by the original author.

TL;DR

Write the postmortem for the incident customers experienced, not the one engineering debugged. Impact in numbers, a timeline anyone can follow, what support told customers and when, and action items with names and dates. If the postmortem cant be read by a support agent who wasnt in the room, it failed.

The query

postmortem template for support-visible incidents

Use this when

• An outage or incident affected customers
• You need a standard incident review format
• Leadership asks "what happened" after an incident
• Follow-up actions keep evaporating

Not for

• Running the blameless debrief meeting itself
• Customer-facing apology or explanation
• Engineering-only technical deep dives
• Minor bugs that never reached customers

Steps

1. Write the summary for a non-technical reader

Three sentences: what customers experienced, how long it lasted, what the cause was. No jargon. If support leadership cant forward it as-is, rewrite it.

Expected output: a summary anyone in the company can understand.

2. Quantify the customer impact

How many accounts, how many tickets, what workflows broke, any data implications. Numbers, not adjectives. This section justifies every action item below it.

Expected output: impact stated in counts and scope.

3. Build the timeline from detection to resolution

Timestamps for: first customer report, internal detection, escalation, mitigation, full resolution, all-clear communication. Include the gaps; the gaps are where the lessons live.

Expected output: a minute-by-minute record with no missing stretches.

4. Record what support told customers and when

Every status update, its time, and its channel. This is the section other templates skip, and it is the one support needs most: did customers hear from us before they heard from each other?

Expected output: a complete communication log alongside the technical timeline.

5. Assign action items with owners and dates

Every lesson becomes a task with a name and a deadline, or it isnt a lesson. "Improve monitoring" is not an action item; "Add an alert for export queue depth, owned by [Name], by [date]" is.

Expected output: a list of owned, dated follow-ups, reviewed at the next incident review.

Ready-to-use template

POSTMORTEM: [incident name, date]

Summary: [3 sentences, plain language]

Customer impact:
- Accounts affected: [count]
- Support tickets: [count]
- Workflows broken: [list]
- Data implications: [none / describe]

Timeline:
- [time] first customer report
- [time] internally detected
- [time] escalated to engineering
- [time] mitigated
- [time] fully resolved
- [time] all-clear sent to customers

Customer communication:
- [time] [channel]: [what we said]

Root cause: [plain-language explanation]

Action items:
- [ ] [task] | Owner: [name] | Due: [date]

Variant phrasings

incident postmortem template for support teams

The template above. The customer-communication section is what makes it support-specific.

how to write a postmortem after an outage

Steps 1 through 3. Summary, impact, timeline, in that order.

support incident review template

Steps 4 and 5. What customers were told, and who owns the fixes.

Why it happens

Postmortems fail support because they are written by engineering for engineering: root cause deep dives with no mention of what customers saw or were told. Support then writes its own shadow version from ticket threads. One template that serves both readers kills the duplication.

Edge cases

• The incident is still sensitive: write the postmortem anyway, mark sections confidential, and distribute narrowly. Skipping the write-up loses the lessons.
• No clear root cause yet: publish with "under investigation" and a follow-up date. A partial postmortem beats a late one.
• Tiny incident, big lesson: still write it, but keep it to the template's bones. The format scales down fine.
• Third-party caused: name the vendor, note their postmortem link, and focus your action items on detection and communication, which you control.
• Repeat of a past incident: link the old postmortem and explain why the action items didnt prevent it. That is the most important section.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstMLyVK5p9QJOg6Q3hsDEuQ

Resolved from the public thread: https://vectle.com/posts/pstMLyVK5p9QJOg6Q3hsDEuQ

Thread query: postmortem template for support-visible incidents

TL;DR: Write the postmortem for the incident customers experienced, not the one engineering debugged. Impact in numbers, a timeline anyone can follow, what support told customers and when, and action items with names and dates. If the postmortem cant be read by a support agent who wasnt in the room, it failed.