Security readout for executives and security teams
Plain-English summary
A synchronization flaw in ESP32-audioI2S 3.4.5 can misreport available audio-buffer space during concurrent activity. Software trusting that result may write beyond allocated memory, potentially crashing the device, corrupting data, or allowing code execution. Business risk depends on whether affected devices expose attacker-controlled audio or network input paths.
Executive priority
Prioritize immediate exposure assessment because the stated worst case is remote code execution with no privileges or interaction. Escalate internet-reachable or safety-critical devices first. Do not claim an active campaign, and do not deploy an assumed fix without confirming current project guidance.
Technical view
AudioBuffer::freeSpace() reportedly reads shared buffer pointers without mutex protection. Concurrent tasks can therefore produce an incorrectly large free-space value, leading callers to perform a heap out-of-bounds write. The record maps this race condition to CWE-362 and assigns CVSS 3.1 score 9.8, but supplied affected-product metadata is incomplete.
Likely exposure
Potentially exposed systems are ESP32 applications incorporating ESP32-audioI2S 3.4.5 and exercising the vulnerable buffer through concurrent tasks. Actual reachability depends on application architecture and whether untrusted input can influence audio-buffer writes. The supplied CVE metadata does not identify CPEs or additional affected versions.
Exploitation context
The supplied record describes possible unauthenticated network exploitation and arbitrary code execution. However, CISA KEV status is false, and the bundle provides no evidence of active exploitation. Treat exploitability in each product as unconfirmed until reachability and attacker-controlled input are validated.
Researcher notes
Evidence supports a race in free-space calculation and a resulting heap out-of-bounds write, but the supplied affected-product fields are listed as n/a. Version scope, vulnerable call paths, and a fixed release are not established in the bundle. Review the referenced source and advisory before making fleet-wide conclusions.
Mitigation direction
- Inventory firmware and projects using ESP32-audioI2S, prioritizing version 3.4.5.
- Check the project repository and CVE advisory for current vendor remediation guidance.
- Restrict untrusted network or audio inputs reaching affected devices until remediation is confirmed.
- Isolate critical affected devices and monitor them for crashes or unexpected restarts.
- Rebuild and redeploy firmware after obtaining a vendor-confirmed corrected release or change.
Validation and detection
- Confirm the exact ESP32-audioI2S version embedded in each firmware image.
- Determine whether concurrent tasks call affected audio-buffer operations.
- Trace whether unauthenticated or untrusted input can influence buffer writes.
- Review crash logs for heap corruption, watchdog resets, or unexplained device failures.
- Verify remediation against updated vendor source and repeat concurrency-focused safety testing.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-362: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-51261 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/schreibfaul1/ESP32-audioI2S/blob/master/src/Audio.cppCVE reference, mitre
- https://github.com/programmervuln/cveadvisory-/blob/main/CVE-2026-51261CVE reference, mitre
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.