CVE-2026-81916Disclosure(concretecms / concrete_cms)

LOWCVSS 4.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

Patch concretecms concrete_cms systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Concrete CMS before 9.5.3 evaluated the authorization check for an Express entry submission against the entity of the posted form rather than the entity identified by the dashboard route. As a result, a user permitted to add entries to one Express object could create entries in a different Express object outside their authorization scope, potentially polluting protected datasets, triggering workflows, or injecting content into administrative processes. The dashboard submit route resolved the mutated entity from the attacker-controlled route ID while the permission check validated the independently posted form's entity, and the submission proceeded because the two entities were never compared. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori from Tenzai for reporting.

concretecms CVEs Back to dashboard

0.5/ 10 priority

Sources & remediation

Other references

https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes

Weakness type (CWE)

CWE-639CWE-862

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

concrete_cms

Threat summary

Patch or workaround signal is available
2 mentions across 2 observed days
Momentum state: stable

What's happening

Patch or workaround mentioned in 1 signal
Technical details provided in 2 signals
Disclosure: 1 classified signal
Peaked 1d ago at 1 mentions (2026-09-13); latest day: 1
2 total mentions across 2 days

Affected systems

Vendors

concretecms

Products

concrete_cms

Deep dive

Activity timeline2 mentions / 2d

Signal classification2 categories

Disclosure

150.0%

Patch

150.0%

Referenced assets2 URLs

By indicator

Classification over time

Date	Total	Labels

2026-09-13	1	Disclosure1
2026-09-20	1	Patch1

Full discourse2 posts

Hugo | DevOps | Cybersecurity 🇱🇻@HugoValters39d
Patch
CVE-2026-81916 Concrete CMS before 9.5.3: broken authorization lets users write to Express objects outside their scope, enabling data pollution and content injection. No CVSS or patch info yet. Update to https://www.valtersit.com/cve/CVE-2026-81916/ #CVE #infosec #ConcreteCMS #cybersecurity #infosec #Microsoft #CVE #infosec #XSS #valtersit #snippet #infosec #SysAdmin #cybersecurity #Linux #devsecops #devops #developer #sysadmin #100daysofcode #git #github #gitlab #redteam #blueteam #ethicalhacker #cybersecurityawareness #cybersecurity #cybersecuritynews #cybersecuritytips #python #hacker #linux #kali #ubuntu #debian #docker
Post summary
CVE-2026-81916 affects Concrete CMS before version 9.5.3, featuring an authorization bypass that allows writing to Express objects and leading to data pollution and injection; the advisory notes no CVSS or patch details yet and urges updating via a provided link.
0000052
1.1K followersView on X
CVE@CVEnew46d
Disclosure
CVE-2026-81916 Concrete CMS before 9.5.3 evaluated the authorization check for an Express entry submission against the entity of the posted form rather than the entity identified by… https://www.cve.org/CVERecord?id=CVE-2026-81916
Post summary
The note highlights a logic vulnerability in Concrete CMS versions 9.5.3 and earlier that mis‑evaluates authorization for Express entries, directing readers to the CVE record for further details.
00000957
58.1K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	concretecms	concrete_cms	-	-	-

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