CVE-2026-10642

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

The Zephyr PL011 UART driver (drivers/serial/uart_pl011.c) contains an unbounded software loop in pl011_irq_tx_enable() that repeatedly invokes the interrupt-driven application callback while the TX interrupt mask bit (PL011_IMSC_TXIM) is set, to work around the controller's level-transition TX-interrupt behavior. When CTS hardware flow control is enabled (devicetree hw-flow-control or runtime UART_CFG_FLOW_CTRL_RTS_CTS) and the wired serial peer de-asserts CTS, the controller stops draining the TX FIFO; pl011_fifo_fill() then returns 0 on every call while the application still has pending data and therefore never disables the TX interrupt. The loop condition never clears, so the thread that called uart_irq_tx_enable() (e.g. h4_send() in the Bluetooth HCI H4 driver) spins indefinitely, hanging the executing context and stalling the transport — a denial of service (CWE-835). An attacker controlling the device attached to the UART's CTS line can trigger the hang by withholding CTS during transmission. Impact is availability only; there is no memory-safety, confidentiality, or integrity consequence. The vulnerable loop was introduced in commit b783bc8448ef (Feb 2025) and shipped in releases v4.1.0 through v4.4.0. The fix breaks out of the loop when CTS is blocking and arms the CTS modem-status interrupt to resume transmission when CTS re-asserts.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
8.2%
KEV
Not listed

Published

June 24, 2026

Last Modified

July 2, 2026

Advisory Details (2)

Auto-updated Jun 25, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Unbounded TX busy-loop DoS in Zephyr PL011 UART driver under CTS hardware flow control · Advisory · zephyrproject-rtos/zephyr · GitHub

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3fgh-73jh-2q5j
github_commit

commit 68e702294b71 (zephyrproject-rtos/zephyr)

Fix landed in zephyrproject-rtos/zephyr commit 68e702294b71 — awaiting tagged release

https://github.com/zephyrproject-rtos/zephyr/commit/68e702294b711eadfe7b4fadedd46d7c87fe8f3d

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 39× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-12 09:52 UTCEG score recompute
  2. 2026-07-12 05:46 UTCEPSS rescore
  3. 2026-07-11 10:40 UTCEG score recompute
  4. 2026-07-10 11:28 UTCEG score recompute
  5. 2026-07-09 19:10 UTCEPSS rescore
  6. 2026-07-09 12:15 UTCEG score recompute
  7. 2026-07-08 15:15 UTCEPSS rescore
  8. 2026-07-08 15:15 UTCEPSS rescore
  9. 2026-07-08 13:03 UTCEG score recompute
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-07 13:43 UTCEG score recompute
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 14:29 UTCEG score recompute
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-05 15:18 UTCEG score recompute
  16. 2026-07-05 02:30 UTCEPSS rescore
  17. 2026-07-05 02:30 UTCEPSS rescore
  18. 2026-07-04 16:04 UTCEG score recompute
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-03 16:51 UTCEG score recompute
  21. 2026-07-02 17:40 UTCEG score recompute
  22. 2026-07-01 18:27 UTCEG score recompute
  23. 2026-07-01 15:06 UTCEPSS rescore
  24. 2026-07-01 15:06 UTCEPSS rescore
  25. 2026-06-30 23:22 UTCEPSS rescore
Show 14 more
  1. 2026-06-30 19:16 UTCEG score recompute
  2. 2026-06-29 20:05 UTCEG score recompute
  3. 2026-06-29 14:06 UTCEPSS rescore
  4. 2026-06-28 20:53 UTCEG score recompute
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 04:56 UTCEPSS rescore
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-27 21:42 UTCEG score recompute
  9. 2026-06-27 03:08 UTCEPSS rescore
  10. 2026-06-26 22:30 UTCEG score recompute
  11. 2026-06-25 23:19 UTCEG score recompute
  12. 2026-06-25 13:49 UTCEPSS rescore
  13. 2026-06-25 00:07 UTCEG score recompute
  14. 2026-06-25 00:03 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-10642?
CVE-2026-10642 is a medium vulnerability published on June 24, 2026. The Zephyr PL011 UART driver (drivers/serial/uartpl011.c) contains an unbounded software loop in pl011irqtxenable() that repeatedly invokes the interrupt-driven application callback while the TX interrupt mask bit (PL011IMSCTXIM) is set, to work around the controller's level-transition TX-interrupt…
When was CVE-2026-10642 disclosed?
CVE-2026-10642 was first published in the National Vulnerability Database on June 24, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-10642 actively exploited?
CVE-2026-10642 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-10642?
CVE-2026-10642 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-10642?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-10642, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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