CVE-2026-95813: e621ng e621ng advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

e621ng versions before 26.09.16 pass untrusted request parameters directly to Rails url_for in PaginatorComponent and controller navigation links, allowing attackers to redirect pagination and navigation controls to attacker-controlled origins. Attackers can supply host, protocol, and port query parameters that are interpreted as URL generation options, causing pagination links to point to malicious domains while the initial page loads from the legitimate site.

Description quoted from the CVE record (assigned by VulnCheck, published 2026-09-22).

Weakness: URL Redirection to Untrusted Site (‘Open Redirect’)

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and a user must take an action. Impact: confidentiality low, integrity low, availability none. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: partial.

Public exploit evidence (Exploit Observer)

Also known as: EUVD-2026-84860, GHSA-7r53-6357-gf8f

VEDAS cluster: VEDAS:DEWDROPLEOPARD

Exploit Observer links 5 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (5)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (3)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-84860
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-7r53-6357-gf8f
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-95813

2 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.003
low predicted chance of attack
VEDAS: 0.988
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Nuclei · Suricata

Who is affected

Product	Affected	Not affected
e621ng e621ng	before 26.09.16	26.09.16 is not affected

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

Fixed versions stated in the CVE record: 26.09.16.

Vendor guidance:

Pull Request #2518 (patch, issue-tracking)
Patch Commit (patch)
e621ng 26.09.16 Release Notes (release-notes)

How to detect it

Nuclei template (active check)

e621ng - Open Redirect via Pagination Host Parameter
e621ng before 26.09.16 passes untrusted request parameters straight into the Rails url_for helper in PaginatorComponent and controller navigation links. An unauthenticated attacker can supply host, protocol and port query parameters that Rails interprets as URL-generation options, so the pagination and navigation links rendered on listing pages (for example /posts) point at an attacker-controlled origin while the page itself still loads from the legitimate site. The template requests a listing page with an attacker host and confirms the vulnerability when that host is reflected into an absolute pagination link in the response body.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (GET /posts?page=2&host={{redir}}&protocol=https); it decides using status, word matchers. Severity in the template: medium. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2026-95813.yaml

Show the template (40 lines)

yaml

id: CVE-2026-95813

info:
  name: "e621ng - Open Redirect via Pagination Host Parameter"
  author: vedas-arpsyndicate
  severity: medium
  description: |
    e621ng before 26.09.16 passes untrusted request parameters straight into the Rails url_for helper in
    PaginatorComponent and controller navigation links. An unauthenticated attacker can supply host, protocol and
    port query parameters that Rails interprets as URL-generation options, so the pagination and navigation links
    rendered on listing pages (for example /posts) point at an attacker-controlled origin while the page itself
    still loads from the legitimate site. The template requests a listing page with an attacker host and confirms
    the vulnerability when that host is reflected into an absolute pagination link in the response body.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-95813&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=e621ng&match=exact
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
    cve-id: CVE-2026-95813
    cwe-id: CWE-601
  metadata:
    verified: false
  tags: cve,cve2026,e621ng,redirect,unauth

variables:
  redir: "vedas{{rand_int(100000,999999)}}.example.com"

http:
  - method: GET
    path:
      - "{{BaseURL}}/posts?page=2&host={{redir}}&protocol=https"
    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "//{{redir}}/"
      - type: status
        status:
          - 200

CVE-2026-95813.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-95813 e621ng - Open Redirect via Pagination Host Parameter. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-95813 e621ng - Open Redirect via Pagination Host Parameter"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"host="; nocase; content:"protocol="; nocase; pcre:"/[?&]host=[a-z0-9][a-z0-9.-]*\.[a-z]{2,}(?:&|$)/i"; classtype:web-application-attack; reference:cve,CVE-2026-95813; reference:url,https://www.exploit.observer/?keyword=CVE-2026-95813&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=e621ng&match=exact; sid:1079401; rev:1;)

CVE-2026-95813.rules on GitHub

References

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.