Bounded memory over-read via unchecked fragment length
Published Aug 26, 2026 · Updated Aug 26, 2026
Out-of-bounds reads in Zephyr RTOS 3.7.0 through 4.4.1 allow attackers to read adjacent memory via crafted LoRaWAN FUOTA downlinks. frag_transport_package_callback() checks only that one byte remains, then treats the tail as a 10-byte setup request or passes it to a decoder that consumes ctx.frag_size bytes without verifying the remaining payload length. Reachability requires valid LoRaWAN session keys; the extra bytes can enter decoder buffers and the FUOTA flash image, but they are not returned in uplinks and provide no write or control-flow primitive.
Summary
What happened
Out-of-bounds reads in Zephyr RTOS 3.7.0 through 4.4.1 allow attackers to read adjacent memory via crafted LoRaWAN FUOTA downlinks. frag_transport_package_callback() checks only that one byte remains, then treats the tail as a 10-byte setup request or passes it to a decoder that consumes ctx.frag_size bytes without verifying the remaining payload length. Reachability requires valid LoRaWAN session keys; the extra bytes can enter decoder buffers and the FUOTA flash image, but they are not returned in uplinks and provide no write or control-flow primitive.
The record
- CVE
- CVE-2026-13480
- Published
- Aug 26, 2026
- Updated
- Aug 26, 2026
- Vendor
- Zephyr Project
- Product
- Zephyr RTOS
- Classifications
- CWE-125, CWE-20, T1499.004
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 26, 2026CVE publishedPublication date reported by the CVE source.
- Aug 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.7.0 <4.4.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA standalone FUOTA reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo