CVE-2026-53402: Linux kernel · Out-of-bounds Read
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.1 High · fixed in cb016bcb40c81e7b19c4ae6143babb366dae8e20 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 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
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in cb016bcb40c81e7b19c4ae6143babb366dae8e20, b5bb2c696e140c399cb874def2feedf61dee27d6, ac562193c36696513ae196171892e9338475c4bc +8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 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: fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font() When fbcon_do_set_font() fails (e.g., due to a memory allocation failure inside vc_resize() under heavy memory pressure), it jumps to the `err_out` label to roll back the console state. However, the current rollback logic forgets to restore the `hi_font` state, leading to a severe state machine corruption. Earlier in the function, `set_vc_hi_font()` might be called to change `vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()` subsequently fails, the `err_out` path restores `vc_font.charcount` but entirely skips rolling back the `vc_hi_font_mask` and the screen buffer. This mismatch leaves the terminal in a desynchronized state. Because `vc_hi_font_mask` remains set, the VT subsystem will still accept character indices greater than 255 from userspace and write them to the screen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will then use these inflated indices to access the reverted, 256-character font array, leading to a deterministic out-of-bounds read and potential kernel memory disclosure. Fix this by adding the missing rollback logic for the `hi_font` mask and screen buffer in the error path.
References
- git.kernel.org/stable/c/cb016bcb40c81e7b19c4ae6143babb366dae8e20 (opens in a new tab)
- git.kernel.org/stable/c/ac562193c36696513ae196171892e9338475c4bc (opens in a new tab)
- git.kernel.org/stable/c/3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5 (opens in a new tab)
- git.kernel.org/stable/c/a7a526fbc847f07ad3a503c7382189be5ab68574 (opens in a new tab)
- git.kernel.org/stable/c/b5bb2c696e140c399cb874def2feedf61dee27d6 (opens in a new tab)
- git.kernel.org/stable/c/076b1aa65f77a49bce5a48a4a55a397cfcafa2b8 (opens in a new tab)
- git.kernel.org/stable/c/39815715cbcfabb16fc8c5f4a23deeda20f5df62 (opens in a new tab)
- git.kernel.org/stable/c/8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2 (opens in a new tab)