CVE-2026-74733: Linux kernel · gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e6a2f5f845f50b0c4299bace5111f56d3390a090 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in e6a2f5f845f50b0c4299bace5111f56d3390a090, bf3f37c2d40b51deb79aea910f28999d7c8c6b5a, 41255e64eb9dd87b0b8675f4e47a9c67bcef6e39 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: gpio: pca953x: fix pca953x_irq_bus_sync_unlock regmap lock Locking is disabled in the regmap config as this driver uses its own lock. This means that all calls to regmap functions (read or write) must hold the i2c_lock. The function pca953x_irq_bus_sync_unlock() did not do this, and it was therefore possible that multiple threads could cause an incorrect register to be read/written. A previous patch partly fixed this, but only protected the write to the interrupt mask register, and not the read from the direction register.
References
- git.kernel.org/stable/c/5d05c4252c09ce10624be2197853c80bf87424e4 (opens in a new tab)
- git.kernel.org/stable/c/41255e64eb9dd87b0b8675f4e47a9c67bcef6e39 (opens in a new tab)
- git.kernel.org/stable/c/bf3f37c2d40b51deb79aea910f28999d7c8c6b5a (opens in a new tab)
- git.kernel.org/stable/c/e6a2f5f845f50b0c4299bace5111f56d3390a090 (opens in a new tab)
- git.kernel.org/stable/c/9dc325327babe7f159e84cbe9380a45342da0585 (opens in a new tab)