CVE-2026-53402 (GCVE-0-2026-53402)
Vulnerability from cvelistv5 – Published: 2026-07-19 12:02 – Updated: 2026-10-19 20:07
VLAI
EPSS
VEX
Title
fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()
Summary
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.
Severity
7.1 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 15:30 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
868749a7456dc48e93887a8474194e2ee6d6c21f , < cb016bcb40c81e7b19c4ae6143babb366dae8e20
(git)
Affected: ebd6f886aa2447fcfcdce5450c9e1028e1d681bb , < ac562193c36696513ae196171892e9338475c4bc (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 3618a4c5b2591cfa83efe74f5b18c2d02b35c3f5 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < a7a526fbc847f07ad3a503c7382189be5ab68574 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < b5bb2c696e140c399cb874def2feedf61dee27d6 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 076b1aa65f77a49bce5a48a4a55a397cfcafa2b8 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 39815715cbcfabb16fc8c5f4a23deeda20f5df62 (git) Affected: a5a923038d70d2d4a86cb4e3f32625a5ee6e7e24 , < 8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2 (git) Affected: f08ccb792d3eaf1dc62d8cbf6a30d6522329f660 (git) Affected: 5.10.249 , < 5.10.261 (semver) Affected: 5.15.64 , < 5.15.212 (semver) Affected: 5.19.6 , < 5.20 (semver) |
guessed | |
| Linux | Linux |
Affected:
6.0
Unaffected: 0 , < 6.0 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.3 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
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Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.