Vulnerability · CVE-2026-74653
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an R
Published Aug 22, 2026 · catalog updated Oct 15, 2026 · In the Linux kernel,
Check if you run it
No confirmed exploitation is on record for CVE-2026-74653. EPSS is 0.17%. Act only if a listed version of In the Linux kernel, is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (In the Linux kernel,).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.17%
- Remediation
- Advisory link
- Affected products
- Debian:12 linux · Debian:12 linux-6.12 · Debian:13 linux · Debian:14 linux
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT (0x0c) but LSR.DR is clear. A character timeout is only cleared by reading RHR, but serial8250_rx_chars() reads RHR only when LSR.DR is set, so nothing ever clears the condition. The interrupt is level-triggered and re-fires immediately, so on a single-core ARM926 the resulting interrupt storm livelocks the CPU. It is reproducible when userspace repeatedly opens the front-panel port (ttyS1): serial8250_do_set_termios() re-enables interrupts on unlock and the handler then spins forever with iir=0xcc lsr=0x60 ier=0x05, tripping the soft-lockup detector in serial8250_handle_irq_locked(). LPC32xx has no dedicated 8250 glue driver, it's driven by the generic 8250_of. Add a hardware specific handle_irq for PORT_LPC3220, wired up in of_platform_serial_setup() the same way fsl8250_handle_irq is installed. The handler follows dw8250_handle_irq(): on an RX timeout with an empty FIFO (LSR.DR and LSR.BI clear) it does one throwaway RHR read to clear the condition, then calls serial8250_handle_irq_locked(). No real received data is ever discarded, and it is a no-op on healthy UARTs which never report a timeout with DR clear. This is the same class of bug already worked around in other 8250 drivers; see commit 424d79183af0 ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt") which reports the identical iir=0xcc/lsr=0x60. See also UART_RX_TIMEOUT_QUIRK in 8250_omap, and the note in 8250_bcm7271.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
- Debian:12 linux-6.120 → 6.12.107-1~deb12u1
- Debian:13 linux0 → 6.12.107-1
- Debian:14 linux0 → 7.1.9-1
How to fix CVE-2026-74653
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-74653. EPSS is 0.17%. Act only if a listed version of In the Linux kernel, is installed.
Which versions are affected?
Compare what you have installed with 6.1.106-1, 6.1.106-2, 6.1.106-3, 0 → 6.12.107-1~deb12u1, 0 → 6.12.107-1, 0 → 7.1.9-1. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.17%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Aug 22, 2026 · NIST NVD
Detected
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT (0x0c) but LSR.DR is clear. A character timeout is only cleared by reading RHR, but serial8250_rx_chars() reads RHR only when LSR.
Oct 14, 2026 · NIST NVD
Updated
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT (0x0c) but LSR.DR is clear. A character timeout is only cleared by reading RHR, but serial8250_rx_chars() reads RHR only when LSR.
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 6.12.107-1; linux fixed in 7.1.9-1; linux-6.12 fixed in 6.12.107-1~deb12u1
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 6.12.107-1
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux fixed in 7.1.9-1
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Fix available
linux-6.12 fixed in 6.12.107-1~deb12u1
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Updated
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT (0x0c) but LSR.DR is clear. A character timeout is only cleared by reading RHR, but serial8250_rx_chars() reads RHR only when LSR.
Sources
- CVE.orgVulnerability recordCVE-2026-74653
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-74653
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-2026-74653
In the Linux kernel, the following vulnerability has been resolved: serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx The NXP LPC32xx UART (PORT_LPC3220) can latch an RX character-timeout interrupt while the RX FIFO is empty: IIR reports UART_IIR_RX_TIMEOUT (0x0c) b
nvd.nist.gov - OpenSSF OSV / OSV ScannerPackage advisoryDEBIAN-CVE-2026-74653osv.dev
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.