Cyber Resilience

CVE-2026-10652

Memory Safety in Zephyrproject Zephyr 4.3.0 – 4.4.1

Public PoCMemory Safety
Published
30 June 2026
Modified
17 July 2026
Patch / advisory
CVSS Score v3.1 4.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
EPSS Score 0.0031 23th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-10652 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Zephyrproject Zephyr. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 23th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-16 (Memory Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Zephyr's DNS resolver (subsys/net/lib/dns) parses resource records from DNS responses in dns_unpack_answer(), which validated only the fixed RR header (type, class, TTL, rdlength) and accepted any attacker-declared rdlength, including one extending past the end of the received datagram. The TXT…

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and SRV consumers in dns_validate_record() (resolve.c) then read up to rdlength bytes (clamped only to a record-type maximum such as DNS_MAX_TEXT_SIZE, default 64, not to the packet) from the receive buffer via memcpy without their own bounds check, and pass the result to the application's resolve callback. A malicious or spoofed DNS server, an on-path attacker forging UDP DNS replies, or (with mDNS/LLMNR enabled) any LAN node can craft a truncated TXT or SRV response that causes an out-of-bounds read of adjacent receive-pool memory; the disclosed stale bytes (residual contents of prior DNS packets / uninitialized pool memory) are returned to the application as TXT/SRV record contents, an information leak, and may in some configurations cross the allocation boundary and fault, causing a denial of service. The read is bounded (~64 bytes for TXT, ~6 for SRV) and read-only (no write). The fix rejects any record whose declared rdata extends past dns_msg->msg_size at the single chokepoint in dns_unpack_answer(). Affected: v4.3.0 and v4.4.0.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
Why these techniques?

OOB read in DNS RR parsing directly enables extraction of adjacent pool memory contents (stale/uninitialized data) returned via application callback.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-9263Same product: Zephyrproject Zephyr
CVE-2025-1675Same product: Zephyrproject Zephyr
CVE-2025-1674Same product: Zephyrproject Zephyr
CVE-2026-10645Same product: Zephyrproject Zephyr
CVE-2026-10657Same product: Zephyrproject Zephyr
CVE-2025-1673Same product: Zephyrproject Zephyr
CVE-2026-5071Same product: Zephyrproject Zephyr
CVE-2023-0396Same product: Zephyrproject Zephyr
CVE-2024-6443Same product: Zephyrproject Zephyr
CVE-2026-8023Same product: Zephyrproject Zephyr

Affected Assets

zephyrproject
zephyr
4.3.0 — 4.4.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-16 Memory Protection
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces validation of DNS response RDATA lengths against actual message size before any rdlength-driven memcpy in dns_unpack_answer and dns_validate_record.

prevent

Hardware or OS memory protection can bound or fault on the out-of-bounds read of adjacent receive-pool memory when an attacker-supplied rdlength exceeds the datagram.

detect

Continuous monitoring of DNS resolver behavior and anomalous record lengths can detect exploitation attempts that produce truncated or oversized TXT/SRV responses.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
detects

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References