Security readout for executives and security teams
Plain-English summary
Helm could be told to require plugin signature verification, yet still install a plugin when its provenance file was missing. That means a control meant to block unsigned plugins could silently fail. The issue affects Helm 4.0.0 through 4.1.3 and is fixed in 4.1.4.
Executive priority
Treat this as a high-priority supply-chain control failure for Kubernetes tooling. Prioritize environments where Helm plugins are installed in CI/CD or by cluster administrators, because verification expectations may have been bypassed.
Technical view
CVE-2026-35205 is a fail-open verification flaw in Helm plugin installation. When verification was required, Helm accepted plugins without a .prov provenance file. The CVE maps to CWE-347 and CWE-636, has CVSS 4.0 score 8.4, requires user action, and affects Helm >=4.0.0 and <4.1.4.
Likely exposure
Exposure is most likely on developer, administrator, or CI/CD systems using Helm 4.0.0 through 4.1.3 to install plugins with verification expected. The bundle does not identify Helm 3 as affected.
Exploitation context
The source bundle does not show KEV listing or confirmed active exploitation. Abuse would require a user or automation path that installs a Helm plugin while relying on verification to reject unsigned content.
Researcher notes
The key issue is not cryptographic breakage but missing-provenance handling. Helm’s verification path failed open when the .prov file was absent. The fix is referenced in Helm commit 05fa37973dc9e42b76e1d2883494c87174b6074f and release v4.1.4.
Mitigation direction
- Upgrade Helm to version 4.1.4 or later.
- Inventory CI/CD images, build agents, and admin workstations for affected Helm versions.
- Review vendor advisories, especially Red Hat guidance, for packaged Helm updates.
- Avoid installing Helm plugins that lack expected provenance files.
- Restrict plugin sources to trusted repositories pending full remediation.
Validation and detection
- Confirm installed Helm versions are not 4.0.0 through 4.1.3.
- Check CI/CD base images and developer toolchains for bundled Helm versions.
- Verify plugin governance requires provenance where signature verification is expected.
- Review recent Helm plugin installation activity for unexpected or untrusted sources.
- Confirm applicable Red Hat errata or vendor fixes are applied.
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-347: 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 lookupCWE-636: 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 lookupContainer 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.
Open ATT&CK lookupCVE-2026-35205 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
- High
- CVSS
- 8.4 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/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:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——GitHub_MCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H2.15.9redhat-SADPVulnerability scoring details
Base CVSS 4.0 score
8.4HighVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/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.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-04-09T16:01:08.682Z: Reported to Red Hat.
- 2026-04-09T15:06:41.052Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/helm/helm/security/advisories/GHSA-q5jf-9vfq-h4h7CVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/helm/helm/commit/05fa37973dc9e42b76e1d2883494c87174b6074fCVE reference, GitHub_M · x_refsource_MISC
- https://github.com/helm/helm/releases/tag/v4.1.4CVE reference, GitHub_M · x_refsource_MISC
- https://helm.sh/docs/topics/provenance/#the-provenance-fileCVE reference, GitHub_M · x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-35205CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2456927CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35205.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:26441CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
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.
Improper Verification of Cryptographic Signature
Improper Verification of Cryptographic Signature represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Not Failing Securely ('Failing Open')
Not Failing Securely ('Failing Open') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.