Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.46% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-32639High confidence
Winter: Broken access control in `Cms\Controllers\Index` allows cross-template actions and unauthorized asset uploads
wintercms · winter
Official source article: GitHub GHSA-5C4F-9PQ9-6C77 ↗. Check the applicable product and release in the original source.
6.8MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs wintercms winter and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges1 source-attributed range
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| composerwinter/wn-cms-module | <= 1.2.12 | 1.2.13 | GitHub advisory ↗upstream repository advisory · 12 Aug 2026 |
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the CMS section's Theme Editor AJAX handlers did not enforce per-template-type permission checks, allowing a backend user with any single CMS permission to act on template types outside their authorized scope. The CMS controller gated access to the section as a whole using OR-logic across its five permissions, but individual handlers such as onSave(), onDelete(), and onDeleteTemplates() did not verify that the user held the specific permission for the requested template type, so a user with only cms.manage_pages could craft AJAX requests to delete layouts, modify partials, or read content files. Separately, the AssetList widget was registered for any user who passed the controller gate regardless of the cms.manage_assets permission, and its onUpload() handler omitted the theme-validation call present on the other mutating handlers, permitting unauthorized file uploads into the active theme's asset directory. Exploitation requires an authenticated backend account holding at least one of the CMS Theme Editor permissions. This issue is fixed in version 1.2.13.
What
Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the CMS section's Theme Editor AJAX handlers did not enforce per-template-type permission checks, allowing a backend user with any single CMS permission to act on template types outside their authorized scope. The CMS controller gated access to the section as a whole using OR-logic across its five permissions, but individual handlers such as onSave(), onDelete(), and onDeleteTemplates() did not verify that the user held the specific permission for the requested template type, so a user with only cms.manage_pages could craft AJAX requests to delete layouts, modify partials, or read content files. Separately, the AssetList widget was registered for any user who passed the controller gate regardless of the cms.manage_assets permission, and its onUpload() handler omitted the theme-validation call present on the other mutating handlers, permitting unauthorized file uploads into the active theme's asset directory. Exploitation requires an authenticated backend account holding at least one of the CMS Theme Editor permissions. This issue is fixed in version 1.2.13.
Why
The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the CMS section's Theme Editor AJAX handlers did not enforce per-template-type permission checks, allowing a backend user with any single CMS permission to act on template types outside their authorized scope. The CMS controller gated access to the section as a whole using OR-logic across its five permissions, but individual handlers such as onSave(), onDelete(), and onDeleteTemplates() did not verify that the user held the specific permission for the requested template type, so a user with only cms.manage_pages could craft AJAX requests to delete layouts, modify partials, or read content files. Separately, the AssetList widget was registered for any user who passed the controller gate regardless of the cms.manage_assets permission, and its onUpload() handler omitted the theme-validation call present on the other mutating handlers, permitting unauthorized file uploads into the active theme's asset directory. Exploitation requires an authenticated backend account holding at least one of the CMS Theme Editor permissions. This issue is fixed in version 1.2.13.
Why
The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Authentication Bypass by Alternate Name → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- High: elevated access is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-289 ↗
CWE-289: Authentication Bypass by Alternate Name. The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- winter: < 1.2.13
- Fixed
- 1.2.13.
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 26 Aug 2026 · Last source change 29 Aug 2026, 02:46 UTC · CWE-289 · Authentication Bypass by Alternate Name
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-27
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-66643
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-66643 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-66643"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.