CVE-2026-66882

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Source
https://cve.org/CVERecord?id=CVE-2026-66882
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66882.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-66882
Aliases
Published
2026-08-25T08:03:47Z
Modified
2026-09-03T03:30:55Z
Severity
  • 2.1 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N CVSS Calculator
Summary
Reflected XSS in AshAuthentication confirmation and magic link interaction forms
Details

Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in team-alembic AshAuthentication allows reflected cross-site scripting via the confirmation and magic link interaction forms.

When a strategy is configured with require_interaction? set to true, AshAuthentication serves an intermediate HTML page asking the user to confirm the action by submitting a form. Both such pages embed a request parameter directly into a hidden input's value attribute without HTML escaping: lib/ash_authentication/add_ons/confirmation/confirmation_form.html.eex interpolates the confirm parameter, and lib/ash_authentication/strategies/magic_link/sign_in_form.html.eex interpolates the magic link token parameter. These templates are compiled with EEx.function_from_file/3 using plain <%= %> expressions, which perform no escaping, so the parameter is reflected verbatim.

Neither accept handler validates the value before rendering it. AshAuthentication.AddOn.Confirmation.Plug.accept/2 only checks that a confirm key is present, and AshAuthentication.Strategy.MagicLink.Plug.accept/2 reads the parameter directly, so no token signature is verified at this stage and arbitrary attacker-supplied text reaches the template. An unauthenticated attacker can therefore craft a URL whose parameter terminates the attribute and injects markup, for example a quote followed by a

Database specific 
{
    "cna_assigner": "EEF",
    "cwe_ids": [
        "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66882.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "fe0b4558dbe852fee5d81a460a8355577618a8c8"
                },
                {
                    "fixed": "*"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/team-alembic/ash_authentication

Affected ranges

Type
GIT
Repo
https://github.com/team-alembic/ash_authentication
Events
Introduced
cf2095dda5d489ee37166cfce0905f6bd21f4761
Fixed
5a32a74e99d38b58d5b7e94c986c96356d5cd3e3
Introduced
6767fe27eb952e5bc09aa2e5a7d8f96f5a1c424a
Fixed
d1dc61ad0e5034ee3d41dce6cf83eea94dcd46d3
Fixed
0bd5199db066be22b2ca1ec8bc6109e5d62e6070
Fixed
62719710790a150a9eacab9c0a066e0d122d15be
Database specific
Show details 
{
    "extracted_events": [
        {
            "introduced": "4.8.0"
        },
        {
            "fixed": "4.14.2"
        },
        {
            "introduced": "5.0.0-rc.0"
        },
        {
            "fixed": "5.0.0-rc.13"
        }
    ],
    "source": [
        "DESCRIPTION",
        "REFERENCES"
    ]
}

Affected versions

5.*
5.0.0-rc.8
5.0.0-rc.9
v4.*
v4.10.0
v4.11.0
v4.12.0
v4.13.0
v4.13.1
v4.13.2
v4.13.3
v4.13.4
v4.13.5
v4.13.6
v4.13.7
v4.14.0
v4.14.1
v4.8.0
v4.8.1
v4.8.2
v4.8.3
v4.8.4
v4.8.5
v4.8.7
v4.9.0
v4.9.1
v4.9.2
v4.9.3
v4.9.4
v4.9.5
v4.9.6
v4.9.7
v4.9.8
v4.9.9
v5.*
v5.0.0-rc.0
v5.0.0-rc.1
v5.0.0-rc.10
v5.0.0-rc.11
v5.0.0-rc.12
v5.0.0-rc.2
v5.0.0-rc.3
v5.0.0-rc.4
v5.0.0-rc.5
v5.0.0-rc.6
v5.0.0-rc.7

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66882.json"