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.
CVE-2026-34961
HIGHNVD 7.77.7
EchelonGraph scoreMEDIUM confidence
“—” beside the score: it is equal to NVD's CVSS score.
This high-severity CVE scores 7.7 under NVD CVSS v3. EPSS exploit probability: 0.2% (10th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 6.2 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-05-12) is not newer than that change (2026-11-11), so it does not.
Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Also known asEUVD-2026-29323 (ENISA EUVD) · GHSA-vv9w-vff6-5rx9 (GitHub Security Advisories)Source: ENISA EUVD
7.7EG
EchelonGraph verdictPlan mitigationNo release containing the referenced fix is confirmed: check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.7Exploit: None knownExposed services: —
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).
Internet exposure
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- CVSS v3
- 7.7
- EG Score
- 7.7HIGHmedium confidence
- EG Risk
- 35EG Risk 35/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity77% × 45%Impact severity (EG Severity): CVSS 7.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.2% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule. - EPSS PROB
- 0.2%
- EPSS %ILE
- 10th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.7): severity, escalated by confirmed exploitation. This CVE's 7.7 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.7 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-11). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
May 11, 2026
Last Modified
November 11, 2026
Advisory Details (3)
Auto-updated May 11, 2026Fix referenced — no release confirmed yet.
Web page
barebox ext4 Extent Parsing Out-of-Bounds Read | Advisories | VulnCheck
https://www.vulncheck.com/advisories/barebox-ext4-extent-parsing-out-of-bounds-readWeb page
Release v2026.04.0 · barebox/barebox · GitHub
https://github.com/barebox/barebox/releases/tag/v2026.04.0Web page
GitHub - barebox/barebox: The barebox bootloader - Mirror of ssh://[email protected]/barebox · GitHub
https://github.com/barebox/bareboxVendor Advisories for CVE-2026-34961(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patches & affected packages
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Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-34961?
CVE-2026-34961 is a high-severity vulnerability; its CVE record was published on May 11, 2026. 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…
When was CVE-2026-34961 made public?
CVE-2026-34961 was made public on May 10, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on May 11, 2026. EchelonGraph's copy of the record carries a last-modified date of November 11, 2026; the record at its source may have been updated since.
Is CVE-2026-34961 actively exploited?
CVE-2026-34961 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-34961?
CVE-2026-34961 has a CVSS v3 base score of 7.7 (NVD).
How do I remediate CVE-2026-34961?
A fix for CVE-2026-34961 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-34961 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-34961
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