CVE-2026-81507: ESF-IDF: Bluetooth Classic L2CAP Heap Memory Disclosure Allowing Unauthorized Access to Sensitive Data
Noroxi assessment
Priority: Monitor (action score 26/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.26% (FIRST EPSS).
- Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: espressif esp-idf 5.2.8.
Low priority for now. Upgrade to espressif esp-idf 5.2.8 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. Prior to 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1, ESP-IDF BlueDroid L2CAP configuration-option processing in l2c_main.c and l2c_utils.c does not consistently validate option lengths against the remaining received packet bytes. A remote unauthenticated BR/EDR peer within radio range can send a malformed L2CAP configuration request that causes an out-of-bounds read, and under some runtime conditions limited adjacent Bluetooth stack memory can be included in an outbound L2CAP Configuration Response. The issue affects ESP32-class products using the BlueDroid host stack with Classic Bluetooth enabled. This issue is fixed in 5.2.8, 5.3.6, 5.5.5, 6.0.3, and 6.1-rc1.
- Published
- Oct 13, 2026
- Updated
- Oct 16, 2026
- EPSS
- 0.2% · 18th percentile
- CWE
- CWE-125
Report tools
Action score
26
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 6.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
espressif esp-idf
- < 5.2.8, >= 5.3-beta1, < 5.3.6, >= 5.4-beta1, < 5.5.5, >= 6.0-beta1, < 6.0.3, >= 6.1-beta1, < 6.1-rc1affected
Same product
espressif: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-113780ESF-IDF: Unvalidated Stack Pointer at the ESP-TEE Privilege-Switch Boundary37Monitor
- CVE-2026-45328ESF-IDF: Out-of-Bounds Write in ESP-TEE Secure Service Wrappers35Monitor
- CVE-2024-53406Espressif Esp idf v5.3.0 is vulnerable to Insecure Permissions resulting in Authentication bypass.35Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-55687Jul 10, 2026 · ESF-IDF: Stack-Based Out-of-Bounds Write in JPEG Decoder DQT Marker Parsing30Monitor
- ← EarlierCVE-2026-81508Sep 24, 2026 · ESF-IDF: Heap Out-of-Bounds Read in Bluedroid A2DP Sink Media Packet Processing17Monitor
- Later →CVE-2026-113782Nov 4, 2026 · ESP-IDF: Stack-Based Out-of-Bounds Write in Thread Border Router ND6 Option Parsing28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| espressif esp-idf | 5.2.8 · description | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 13, 2026+31 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2025-65092326 days apartESP32-P4 JPEG Decoder Header Parsing Vulnerability27Monitor
- CVE-2026-45160126 days apartESF-IDF: Out-of-bounds Read in lwIP DHCP Server Option Parser26Monitor
- CVE-2026-25508251 days apartESF-IDF Has Memory Safety Vulnerabilities in BLE Provisioning25Monitor
- CVE-2026-46532126 days apartESF-IDF: Heap Out-of-Bounds Read in Bluedroid AVRCP Target Parser18Monitor
- CVE-2026-8150819 days apartESF-IDF: Heap Out-of-Bounds Read in Bluedroid A2DP Sink Media Packet Processing17Monitor
- CVE-2025-66409315 days apartESF-IDF has an Out-of-Bounds Read in ESP32 Bluetooth AVRCP Command Handling10Monitor
Not on record for this CVE: researcher credit · public bounty program.
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Adjacent
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- SSVC exploitation— → none
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (12 more)Show less
- github.com/espressif/esp-idf/commit/1e07f6d83ca892630a7210df2958455f7ca77b4a
- github.com/espressif/esp-idf/commit/5731c63ece128f156939b9f734256e2227c1442a
- github.com/espressif/esp-idf/commit/8de265dc44b1b22c749ea44ee7c609b3da4162f0
- github.com/espressif/esp-idf/commit/9a6d04f65e0e341e7d72bd417c9f31b8a04ce846
- github.com/espressif/esp-idf/commit/c2610255a5adce651ca582bb82368c3dd0ee2834
- github.com/espressif/esp-idf/commit/c8cd8f4f3019ae2f912c8cbe9974445e8d9b8749
- github.com/espressif/esp-idf/releases/tag/v5.2.8
- github.com/espressif/esp-idf/releases/tag/v5.3.6
- github.com/espressif/esp-idf/releases/tag/v5.5.5
- github.com/espressif/esp-idf/releases/tag/v6.0.3
- github.com/espressif/esp-idf/releases/tag/v6.1-rc1
- github.com/espressif/esp-idf/security/advisories/GHSA-v335-fxwc-rc44
Vendor advisories and official records. Exploit/PoC links are deliberately left out.