CVE-2026-81508 — ESF-IDF: Heap Out-of-Bounds Read in Bluedroid A2DP Sink Media Packet Processing
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Espressif Esp-idf).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.3 | CVSS 3.1 | Medium | 2.8 | 1.4 | security-advisories@github.com via NIST National Vulnerability Database |
| 4.3 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · espressif/esp-idf
- SSVC assessment updated
- Record published
- CVSS changed · 4.3
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
- github.com/espressif/esp-idf/security/advisories/GHSA-xcpr-5mqp-9qvv
- github.com/espressif/esp-idf/commit/6cb20db4dfeee81314d0c55acb82f3f0e7679abe
- github.com/espressif/esp-idf/commit/0d118139ff8b7aa87b656c2f4a6421ecaa1f5939
- github.com/espressif/esp-idf/commit/85d56bcd266117e0fe6a6b75511c8e122fda29ad
- github.com/espressif/esp-idf/commit/ca55d63de82e41e2c672bfd2b707fc80911f30ce
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-81507 ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data 2d
- High CVE-2026-55687 ESF-IDF: Stack-Based Out-of-Bounds Write in JPEG Decoder DQT Marker Parsing Jul 10, 2026
- Medium CVE-2026-46532 ESF-IDF: Heap Out-of-Bounds Read in Bluedroid AVRCP Target Parser Jun 9, 2026
- High CVE-2026-45542 ESF-IDF: Heap buffer overflow in protocomm Security2 over Bluetooth Jun 9, 2026
- Medium CVE-2026-45160 ESF-IDF: Out-of-bounds Read in lwIP DHCP Server Option Parser Jun 9, 2026
- High CVE-2026-45328 ESF-IDF: Out-of-Bounds Write in ESP-TEE Secure Service Wrappers Jun 9, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-81508 is "ESF-IDF: Heap Out-of-Bounds Read in Bluedroid A2DP Sink Media Packet Processing", rated Medium. It affects Esp-idf (Espressif); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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