CVE-2026-12068: Avira Password Manager Credential Theft via Firefox Cross-Origin Iframe

Technical summary

CVE-2026-12068 is an information disclosure vulnerability in Avira Password Manager that stems from improper autofill field selection logic. When Firefox renders a page containing a cross-origin iframe, Avira's extension fails to correctly validate the origin context before populating password fields. The vulnerability allows a remote attacker to construct a malicious webpage with an iframe pointing to a legitimate authentication endpoint, causing the password manager to autofill stored credentials into the attacker-controlled iframe rather than the intended parent page context. This bypasses same-origin policy protections at the application layer. The issue is classified under CWE-669 (Incorrect Initialization with Hard-Coded Network Resource Configuration), though the root cause is more accurately an origin validation failure in the autofill mechanism.

Business impact

This vulnerability creates direct credential theft risk for Avira Password Manager users. In a real-world attack scenario, an attacker hosts a phishing page containing hidden iframes that trick the password manager into autofilling credentials. Those credentials are then captured and exfiltrated, giving attackers immediate access to user accounts across multiple services. The impact scales with the number of stored credentials in Avira's vault. Organizations whose employees use Avira Password Manager—particularly in bring-your-own-device environments—face elevated account compromise risk, including potential lateral movement if stolen credentials are for corporate services. The Firefox-specific scope limits exposure compared to a browser-agnostic vulnerability, but Firefox remains widely deployed in enterprise and consumer settings.

Affected systems

Avira Password Manager when integrated with Mozilla Firefox on Windows, macOS, and Linux platforms. The vulnerability requires user interaction (visiting a malicious webpage) and the Firefox browser specifically; Chrome, Edge, Safari, and other browsers are not affected. All versions of Avira Password Manager using the vulnerable autofill logic are in scope, though specific version ranges were not provided in the advisory data.

Exploitability

This vulnerability has moderate-to-high exploitability. The CVSS score of 7.4 reflects that no special privileges or complex configuration is required (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N). The attack requires user interaction—a victim must visit a malicious website—but the attacker needs no authentication and the attack is network-accessible. The cross-origin iframe technique is well-known and straightforward to implement. There is no evidence of active exploitation in the wild (KEV status: false), but the barrier to weaponization is low. A motivated attacker could deploy this attack at scale via ad networks, watering-hole campaigns, or phishing emails containing malicious links.

Remediation

Update Avira Password Manager to a patched version released after CVE-2026-12068 was published on June 12, 2026 (advisory modified June 17, 2026). Verify the specific patched version against Avira's official security advisory. In the interim, users can reduce risk by disabling autofill in Avira Password Manager settings and manually entering credentials, or by using alternative browsers until patched. Organizations should communicate the need to patch to any users or contractors running this configuration.

Patch guidance

Avira Password Manager users should check Avira's official security advisory and release notes to identify the patched version number specific to their platform (Windows, macOS, or Linux). Update through Avira's standard update mechanism or manual download from Avira's website. Firefox users are not required to update; the fix must come from Avira. After patching, verify that autofill functionality works correctly on trusted websites and that the origin validation logic is properly enforced. Test with a cross-origin iframe proof-of-concept (available in Avira's advisory) to confirm the vulnerability is resolved.

Detection guidance

Monitor for exploitation attempts by logging access to password manager autofill events and correlating them with cross-origin iframe contexts. Security tools should flag password manager activity originating from iframe sources that differ from the main document origin. Endpoint detection and response (EDR) platforms can identify credential exfiltration patterns following a potential attack (e.g., unusual authentication attempts from stolen credentials shortly after a user visits a suspicious page). User reports of unexpected password changes or account lockouts following web browsing are also indicators. Network-level detection is limited since the attack occurs within the browser context.

Why prioritize this

Prioritize patching this vulnerability because it directly enables credential theft with minimal attacker effort, affects all major operating systems, and requires only that a user visit a malicious website. While KEV status is false (no evidence of active exploitation), the simplicity of the attack makes weaponization likely once awareness increases. The high CVSS score (7.4) and broad user base of Firefox justify rapid remediation. Organizations using Avira Password Manager should treat this as a high-priority patch.

Risk score, explained

CVSS 7.4 (HIGH) reflects the combination of high confidentiality impact (credentials fully disclosed), network-accessible attack vector, low attack complexity, and no privilege requirements. The score appropriately penalizes the requirement for user interaction (clicking a malicious link) but still classifies the risk as HIGH given the direct credential theft impact and cross-site scope (S:C). The absence of integrity or availability impact prevents a critical rating, but the confidentiality compromise of sensitive authentication data justifies the HIGH severity designation.

Frequently asked questions