CVE-2026-77939

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

Not scored by EPSS

EPSS percentile

Not scored by EPSS

NVD base score

7.1 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Received. NVD last modified this record on 2026-08-28.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-28 17:06Z13 HR AGO

Last updated

2026-08-28 20:21Z9 HR AGO

Reserved

2026-08-21

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 7.1)

CNA CVSS vector

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

Weaknesses

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

Data version

5.2

Document digest

bdbd52652e06b0472257fe2576818ab93b09752946622006515f2cbebd281d75

• github.comResearcher Disclosurehttps://github.com/flextype/flextype/issues/595technical-descriptionexploit
• www.vulncheck.comhttps://www.vulncheck.com/advisories/flextype-cms-dev-rce-via-post-api-v1-query-endpointthird-party-advisory