Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
zephyrproject zephyr — Use-after-return in `zsock_getaddrinfo()` when a timed-out DNS query is retried without cancellation
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H N N U N H H 7.4 .0032 24.9 —
AFFECTED
Product Versions Fixed
zephyr 3.7.0 – —
TIMELINE
Jun 2 Reserved by zephyr
Jun 28 EXPLOIT PUBLISHED — CVE-2026-10646 (zephyrproject zephyr). Public exploit reference added.
Jun 28 Published (CNA: zephyr)
Aug 6 EXPLOIT PUBLISHED — CVE-2026-10646 (zephyrproject zephyr). Public exploit reference added.
Description
Zephyr's BSD-sockets getaddrinfo() implementation (subsys/net/lib/sockets/getaddrinfo.c) passes a pointer to a stack-allocated state object (struct getaddrinfo_state ai_state) as the user_data of an asynchronous DNS resolver query. The socket layer waits on a semaphore with a timeout deliberately set slightly longer than the resolver's own per-query timeout. When that semaphore wait nonetheless times out (-EAGAIN) - which can occur when the resolver's timeout work is delayed by workqueue contention, or in the documented multi-retry configuration where CONFIG_NET_SOCKETS_DNS_TIMEOUT exceeds CONFIG_NET_SOCKETS_DNS_BACKOFF_INTERVAL - the pre-fix code retries the query (goto again) without cancelling the previous one and without resetting the semaphore.
The previous query slot remains active in the resolver with its callback and the stack pointer as user_data, and ai_state->dns_id is overwritten so the stale query can no longer be cancelled. A subsequent DNS response delivered over UDP and matched by its 16-bit transaction id (in dispatcher_cb()/dns_read()), or the resolver's own delayed query-timeout work, then invokes dns_resolve_cb() against the now out-of-scope stack frame, writing through the stale pointer (state->status, state->idx, state->ai_arr[], and k_sem_give()).
Because the triggering response is network-delivered and its 16-bit id is spoofable/replayable by an on- or off-path attacker, this is a network-influenceable use-after-return that can corrupt reused stack memory, leading to crashes/denial of service or memory corruption.
The fix cancels the timed-out query by name and type before retrying and resets the local semaphore, eliminating the stale callback path. Affected: Zephyr v4.0.0 through v4.4.0.
Lifecycle
Complete event history — 4 events, chronological
| Date | Event | Detail |
|---|
| June 2, 2026 | Reserved | Reserved by zephyr |
| June 28, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-10646 (zephyrproject zephyr). Public exploit reference added. |
| June 28, 2026 | Published | Published (CNA: zephyr) |
| August 6, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-10646 (zephyrproject zephyr). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| zephyrproject | zephyr | — | 3.7.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-10646 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.