ESP32-audioI2S: Out-of-bounds Read
CVE-2026-87961 is a high-severity out-of-bounds read vulnerability in ESP32-audioI2S from Schreibfaul1, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected ESP32-audioI2S versions: 3.4.4 through 4.0.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.47% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of ESP32-audioI2S you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Schreibfaul1 | ESP32-audioI2S | 3.4.4 through 4.0.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.1 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.1 | High | CNA (vulncheck.com) |
Official description
ESP32-audioI2S versions 3.4.4 through 4.0.0 contain a heap-based out-of-bounds read vulnerability in the read_ID3_Header function due to a shadowed length parameter in ID3 synchronized-lyrics processing. Attackers can craft malicious MP3 files or HTTP audio streams with oversized frame size declarations to read past allocated buffer boundaries, causing device crashes or exposing adjacent heap memory.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
References
Patches and release notes
Other references
- github.com/schreibfaul1/ESP32-audioI2S
- github.com/schreibfaul1/ESP32-audioI2S/blob/490ff729eca344f06581f3e9bda9cfba948fd5a1/src/Audio.cpp#L2526-L2531
- github.com/schreibfaul1/ESP32-audioI2S/blob/490ff729eca344f06581f3e9bda9cfba948fd5a1/src/Audio.cpp#L2629-L2635
- github.com/schreibfaul1/ESP32-audioI2S/blob/f01ad7923dcf3355eeca7fb99bf8a4d9945e7478/src/Audio.cpp#L2270-L2276
- github.com/schreibfaul1/ESP32-audioI2S/issues/1380
- vulncheck.com/advisories/esp32-audioi2s-3.4.4-through-4.0.0-heap-based-out-of-bounds-read-via-shadowed-length…
Recent Out-of-bounds Read vulnerabilities
- 8.2 High severity
- 7.1 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.2 High severity
- 9.6 Critical severity
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