Security readout for executives and security teams
Plain-English summary
This issue can make barebox hang while reading a malicious ext4 filesystem image. For affected boot flows, that can stop a device from starting or resolving files during boot. The business impact is availability loss, mainly where devices accept, mount, or boot from ext4 media or images that are not tightly controlled.
Executive priority
Treat this as a targeted availability risk for embedded or appliance environments, not a broad enterprise emergency. Prioritize systems where boot availability matters and where external or semi-trusted media can be introduced.
Technical view
In barebox before 2026.04.0, ext4fs_iterate_dir() in fs/ext4/ext4_common.c does not reject directory entries with a zero length. A crafted ext4 directory entry can keep directory iteration from advancing, causing an infinite loop during directory listing or path resolution. The reported impact is denial of service only.
Likely exposure
Exposure is most likely in products or operational workflows using barebox before 2026.04.0 that parse ext4 filesystems during boot, recovery, provisioning, or diagnostics. Risk increases if removable media, update images, factory images, or customer-supplied filesystem images can reach barebox.
Exploitation context
The bundle does not cite active exploitation, and the CVE is not marked KEV. The attack is local in the CVSS vector and requires a malicious ext4 filesystem image. No source in the bundle supports remote exploitation, data theft, or integrity compromise.
Researcher notes
The key condition is a zero direntlen causing ext4 directory iteration not to advance. The public bundle identifies CWE-835 and availability impact only. Evidence is incomplete on downstream affected vendors, real-world exploit use, and whether all distributions include the upstream fix.
Mitigation direction
- Upgrade barebox to version 2026.04.0 or later where feasible.
- Check downstream device vendors for patched bootloader builds and update guidance.
- Restrict use of untrusted removable media and ext4 images in boot paths.
- Validate provenance and integrity of provisioning, recovery, and update images.
- For unsupported products, ask the vendor for a backport or compensating controls.
Validation and detection
- Inventory products and firmware builds that include barebox.
- Confirm the barebox version is 2026.04.0 or later.
- Review boot, recovery, and provisioning flows for ext4 filesystem parsing.
- Check whether users or operators can supply boot media or filesystem images.
- Run non-production regression tests for malformed ext4 directory handling.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-835: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-34962 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.9 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.53.6VulnCheckVulnerability scoring details
Base CVSS 4.0 score
6.9MediumVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
6.2MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/barebox/bareboxCVE reference, VulnCheck · product
- https://github.com/barebox/barebox/releases/tag/v2026.04.0CVE reference, VulnCheck · patch
- https://www.vulncheck.com/advisories/barebox-ext4-directory-parsing-infinite-loop-denial-of-serviceCVE reference, VulnCheck · third-party-advisory
- Blog PostCVE reference, VulnCheck · technical-description
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Loop with Unreachable Exit Condition ('Infinite Loop')
Loop with Unreachable Exit Condition ('Infinite Loop') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.