Write `docs/security.md` — unified security policy update

[Nursca]

Description
The current SECURITY.md is generic. It needs to be updated to reflect the full ILN ecosystem (contracts, SDK, indexer, notifications) with component-specific vulnerability classes, reporting procedures, and response timelines.

Requirements and context

• Vulnerability classes per component: Soroban contract (reentrancy, storage collision), SDK (XDR encoding bugs, signing bypass), indexer (SQL injection, API abuse), notifications (HMAC bypass, SSRF via webhook URL)
• Reporting instructions (email or private GitHub Security Advisory)
• Response timeline commitments: acknowledgment within 48 hours, fix timeline for critical/high/medium
• Safe harbour statement for good-faith researchers
• Severity classification table

Suggested execution

git checkout -b docs/security-policy-update

• Update SECURITY.md
• Get maintainer review before merging

Example commit message
docs: update SECURITY.md with ecosystem-wide vulnerability guidance

[gloskull]

Hi, I’d love to work on this issue. I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I understand the task clearly and can deliver a clean, efficient, well-tested solution on time, with strong focus on code quality and maintainability. My PR will be submitted in under 10 hours.

[gloskull]

Hi, I’d love to work on this issue. I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I understand the task clearly and can deliver a clean, efficient, well-tested solution on time, with strong focus on code quality and maintainability. My PR will be submitted in under 10 hours.

[OpadijoIdris]

@OpadijoIdris has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I would love to work on this task. Please assign

ℹ️ Repo Maintainers: To accept this application, review their application or assign @OpadijoIdris to this issue.

[TheShnider]

@TheShnider has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi. I have reviewed this issue and would like to work on it.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @TheShnider to this issue.

[Davidemulo]

@Davidemulo has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

i will love to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Davidemulo to this issue.

[sanusishafii989]

@sanusishafii989 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I would like to work on this issue because I have a strong background in technical writing and a keen interest in cybersecurity. Updating the security documentation to reflect the latest unified security policy is crucial for maintaining the integrity and trustworthiness of the network, and I'm confident in my ability to deliver clear, concise, and comprehensive documentation for this project.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @sanusishafii989 to this issue.

[devJaja]

@devJaja has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Can I handle this issue please
ETA 2 hours

ℹ️ Repo Maintainers: To accept this application, review their application or assign @devJaja to this issue.

[Muhamadmust]

@Muhamadmust has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer
I gave reviewed this issue and would love to work on it, PR 1day

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Muhamadmust to this issue.

[drips-wave]

Congratulations, @Davidemulo! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Davidemulo: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

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[grantfox-oss]

🦊 GrantFox — @Davidemulo has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #299)
2. Your PR will be reviewed by the Invoice-Liquidity-Network maintainers

Good luck! Track your progress on GrantFox.