Vulnerability-Lookup

GHSA-J8RR-2WMH-Q2H8

Vulnerability from github – Published: 2026-08-28 21:31 – Updated: 2026-08-28 21:31

Details

Flextype CMS through v1.0.0-dev contains an expression language injection vulnerability that allows authenticated attackers with a valid API token to read arbitrary files by passing unsanitized user-supplied input to the Symfony ExpressionLanguage engine via the POST /api/v1/query endpoint. Attackers can leverage exposed application objects including filesystem() and serializers() within the evaluation scope to read arbitrary server files and achieve conditional remote code execution if a PHP file can be placed on disk through a secondary vector.

Severity

6.5 (Medium)


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

7.1 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-77939"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T20:19:56Z",
    "severity": "HIGH"
  },
  "details": "Flextype CMS through v1.0.0-dev contains an expression language injection vulnerability that allows authenticated attackers with a valid API token to read arbitrary files by passing unsanitized user-supplied input to the Symfony ExpressionLanguage engine via the POST /api/v1/query endpoint. Attackers can leverage exposed application objects including filesystem() and serializers() within the evaluation scope to read arbitrary server files and achieve conditional remote code execution if a PHP file can be placed on disk through a secondary vector.",
  "id": "GHSA-j8rr-2wmh-q2h8",
  "modified": "2026-08-28T21:31:18Z",
  "published": "2026-08-28T21:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77939"
    },
    {
      "type": "WEB",
      "url": "https://github.com/flextype/flextype/issues/595"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/flextype-cms-dev-rce-via-post-api-v1-query-endpoint"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-77939 (GCVE-0-2026-77939)

Vulnerability from cvelistv5 – Published: 2026-08-28 17:06 – Updated: 2026-08-29 11:47 X_Open Source

Title

Flextype CMS 1.0.0-dev RCE via POST /api/v1/query Endpoint

Summary

Severity

7.1 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

6.5 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-28 20:21 UTC

CWE

CWE-94 - Improper Control of Generation of Code ('Code Injection')
CWE-1336 - Improper Neutralization of Special Elements Used in a Template Engine

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/flextype/flextype/issues/595	technical-descriptionexploitissue-tracking
https://www.vulncheck.com/advisories/flextype-cms…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
flextype	flextype	Affected: 0 , ≤ 1.0.0-dev (custom) Affected: 0 , ≤ aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d (git)

Date Public

2026-08-28 00:00

Credits

Marxabo Keldibekova

Show details on NVD website

JSON

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  "containers": {
    "adp": [
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        "metrics": [
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            "other": {
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                  },
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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-28T20:21:53.787122Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-J8RR-2WMH-Q2H8

CVE-2026-77939 (GCVE-0-2026-77939)

Tags

Sightings

Nomenclature