PatchTheCVECVE-2026-10655: The asynchronous SNTP client in Zephyr (subsys/net/lib/sntp/sntp.c, sntp_close_async) closed the UDP socket fi
CVE-2026-10655 is a medium-severity flaw (CVSS 6.5) affecting zephyr. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The asynchronous SNTP client in Zephyr (subsys/net/lib/sntp/sntp.c, sntp_close_async) closed the UDP socket file descriptor directly from the calling thread immediately after detaching it from the network socket service, without synchronizing with the socket-service poll thread. The socket service thread polls each socket via zvfs_poll, which (in zsock_poll_prepare_ctx) registers a k_poll_event pointing into the socket's net_context (&ctx->recv_
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 68%) |
| CISA exploited list | No |
| Weakness | CWE-416 |
| Published | 2026-06-30 |
| Last modified | 2026-10-25 |
Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-10655?
zephyr: upgrade to newer than 4.4.1. Exact commands for each OS are on this page.
Is CVE-2026-10655 being exploited?
CVE-2026-10655 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-10655 affect?
CVE-2026-10655 affects zephyr. Severity is medium (CVSS 6.5). The asynchronous SNTP client in Zephyr (subsys/net/lib/sntp/sntp.c, sntp_close_async) closed the UDP socket file descriptor directly from the calling thread immediately after detaching it from the network socket service, without synchronizi
How urgent is CVE-2026-10655?
Priority 41/100. Public exploit reference; Remotely exploitable, no login, no user action
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