barebox: Out-of-bounds Read
CVE-2026-34961 is a high-severity out-of-bounds read vulnerability in barebox, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists version 2026.04.0 as the first without the flaw, so updating barebox to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update barebox to 2026.04.0 or a later version.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (vulncheck.com) |
| CVSS 3.1 | 6.2 | Medium | CNA (vulncheck.com) |
| CVSS 3.1 | 7.7 | High | NVD |
Official description
barebox prior to version 2026.04.0 contains out-of-bounds read vulnerabilities in ext4 extent parsing due to missing validation of the eh_entries field against buffer capacity in fs/ext4/ext4_common.c. Attackers can supply a malicious ext4 filesystem image via USB, SD card, or network boot to trigger heap out-of-bounds reads during boot-time filesystem parsing, potentially redirecting reads to arbitrary disk offsets.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/barebox/barebox/releases/tag/v2026.04.0Release Notes
Third-party and government advisories
- vulncheck.com/advisories/barebox-ext4-extent-parsing-out-of-bounds-readThird Party Advisory
Other references
Other vulnerabilities in barebox
- 7.8 High severity
- 8.2 High severity
Recent Out-of-bounds Read vulnerabilities
- 7.3 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
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