How severe is CVE-2026-26266?

CVE-2026-26266 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-26266 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26266?

CVE-2026-26266 affects Aliasvault. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-26266?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-26266 have an EU (EUVD) identifier?

Yes. CVE-2026-26266 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9332.

When was CVE-2026-26266 published?

CVE-2026-26266 was published on 2026-03-03 and last updated on 2026-06-17.

CVE-2026-26266

CVE-2026-26266 is a critical-severity vulnerability in Aliasvault with a CVSS 3.x base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.3)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9332
Weakness: CWE-79
Affected product: Aliasvault
Published: 2026-03-03
Last modified: 2026-06-17

Description

AliasVault is a privacy-first password manager with built-in email aliasing. A stored cross-site scripting (XSS) vulnerability was identified in the email rendering feature of AliasVault Web Client versions 0.25.3 and lower. When viewing received emails on an alias, the HTML content is rendered in an iframe using srcdoc, which does not provide origin isolation. An attacker can send a crafted email containing malicious JavaScript to any AliasVault email alias. When the victim views the email in the web client, the script executes in the same origin as the application. No sanitization or sandboxing was applied to email HTML content before rendering. This vulnerability is fixed in 0.26.0.[

Frequently asked questions

What is CVE-2026-26266?: AliasVault is a privacy-first password manager with built-in email aliasing. A stored cross-site scripting (XSS) vulnerability was identified in the email rendering feature of AliasVault Web Client versions 0.25.3 and lower. When viewing received emails on an alias, the HTML content is rendered in an iframe using srcdoc, which does not provide origin isolation. An attacker can send a crafted email containing malicious JavaScript to any AliasVault email alias. When the victim views the email in the web client, the script executes in the same origin as the application. No sanitization or sandboxing was applied to email HTML content before rendering. This vulnerability is fixed in 0.26.0.[
How severe is CVE-2026-26266?: CVE-2026-26266 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-26266 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26266?: CVE-2026-26266 affects Aliasvault. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-26266?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-26266 have an EU (EUVD) identifier?: Yes. CVE-2026-26266 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9332.
When was CVE-2026-26266 published?: CVE-2026-26266 was published on 2026-03-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:aliasvault:aliasvault:*:*:*:*:*:*:*:*

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