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CVE Record

CVE-2026-28406: kaniko has tar archive path traversal in build context extraction allows writing files outside destination directory

kaniko is a tool to build container images from a Dockerfile, inside a container or Kubernetes cluster. Starting in version 1.25.4 and prior to version 1.25.10, kaniko unpacks build context archives using `filepath.Join(dest, cleanedName)` without enforcing that the final path stays within `dest`. A tar entry like `../outside.txt` escapes the extraction root and writes files outside the destination directory. In environments with registry authentication, this can be chained with docker credential helpers to achieve code execution within the executor process. Version 1.25.10 uses securejoin for path resolution in tar extraction.

HighCVSS 8.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Kaniko could be tricked into unpacking a crafted build context so files are written outside the intended directory. In CI or Kubernetes build systems, that can damage build integrity and may enable code execution when registry credential helpers are present.

Executive priority

Treat as high priority for build infrastructure. The main risk is compromise of image-build integrity and possible executor-level code execution, not broad internet-facing exploitation based on current evidence.

Technical view

CVE-2026-28406 is a CWE-22 path traversal in chainguard-forks kaniko versions 1.25.4 through before 1.25.10. Tar extraction used filepath.Join with a cleaned entry name but did not enforce containment under the destination. Version 1.25.10 changes extraction path resolution to securejoin.

Likely exposure

Exposure is most likely in CI/CD, container-build, or Kubernetes environments running chainguard-forks kaniko >=1.25.4 and <1.25.10, especially where build context archives can be influenced by users, repositories, or automation.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. A crafted tar entry can escape the extraction root; the advisory says registry-authenticated environments may chain this with docker credential helpers for code execution inside the executor process.

Researcher notes

The core issue is path containment failure during tar extraction: cleaned names were joined to the destination without proving the resolved path stayed inside it. The fix references securejoin in version 1.25.10. Do not assume other kaniko distributions are affected unless separately sourced.

Mitigation direction

  • Upgrade chainguard-forks kaniko to version 1.25.10 or later.
  • Check vendor and Red Hat guidance for environment-specific status.
  • Limit who can supply or modify build context archives.
  • Reduce kaniko job privileges and registry credential scope.
  • Review pipelines using docker credential helpers with kaniko.

Validation and detection

  • Inventory kaniko versions used in CI, Kubernetes, and build images.
  • Flag any chainguard-forks kaniko versions from 1.25.4 through 1.25.9.
  • Identify pipelines accepting externally influenced tar build contexts.
  • Confirm upgraded jobs use kaniko 1.25.10 or later.
  • Review recent build job anomalies and unexpected file writes.
Prepared
Confidence
high
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

CWE-22: File access and web shell behavior lookup

File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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description · low confidence lookup

File access behavior lookup

The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-28406 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L

Official CVE source material

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.

2CVSS vectors
5Timeline events
2ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We 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.

ScoreVersionSeverityVectorExploitImpactSource
8.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L3.14.7redhat-SADP
8.2CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L3.94.2GitHub_M

Vulnerability scoring details

Base CVSS 3.1 score

8.5High
CVSS 3.1 vector shape for CVE-2026-28406Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPkaniko: kaniko: Arbitrary code execution via path traversal in build context archive unpacking
other:Red Hat severity ratingcvssV3_1
  • 2026-02-27T22:02:23.464Z: Reported to Red Hat.
  • 2026-02-27T21:20:52.764Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
chainguard-forkskaniko>= 1.25.4, < 1.25.10Listed
Weakness

CWE details

CWE-22

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-22 · source CWE mapping

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs