VulnSocial

CVE-2026-81913Disclosure(concretecms / concrete_cms)

LOWCVSS 6.1 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Concrete CMS versions 9.5.0 through 9.5.2 are vulnerable to Open Redirect via the rcURL parameter. An attacker can craft a single link on the site's own domain that sends a user to an arbitrary external site immediately after authentication, facilitating phishing and credential theft. The same handling is present in the registration flow, giving a second entry point on sites with registration enabled. Concrete CMS versions prior to 9.5.0 do not include the rcURL parameter or this allowlist and are not affected. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.3 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Michal M. for reporting.

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0.0/ 10 priority

Sources & remediation

Other references
Weakness type (CWE)
CWE-601

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Are you affected?

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

  • concrete_cms

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
concretecms
Products
concrete_cms

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-09-20: 1Technical Details · 2026-09-20: 109-20
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • Hugo | DevOps | Cybersecurity 🇱🇻@HugoValters
    Disclosure

    CVE-2026-81913: Concrete CMS 9.5.0-9.5.2 open redirect via rcURL parameter. Crafted links can send authenticated users to phishing sites, enabling credential theft. No CVSS published, patch status unknown. https://www.valtersit.com/cve/CVE-2026-81913 #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 #CVE #infosec #ConcreteCMS

    Post summary

    The text announces CVE-2026-81913, disclosing an open redirect vulnerability in Concrete CMS 9.5.0-9.5.2 via the rcURL parameter, with technical details but no PoC, exploit, patch, or active exploitation information.

    0000048
    1.1K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appconcretecmsconcrete_cms---

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