CVE-2026-77353

MEDIUMCVSS 4.6/10EPSS 0.17%

Last modified

CVE-2026-77353 is a medium-severity vulnerability rated 4.6/10 on the CVSS scale. Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 5.0.0, Wallos allows authenticated users to inject arbitrary iCalendar properties and events into their exported .ics feed by embedding raw CRLF sequences in subscription names or notes. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 5.0.0, Wallos allows authenticated users to inject arbitrary iCalendar properties and events into their exported .ics feed by embedding raw CRLF sequences in subscription names or notes. Because the input validation layer only encodes HTML metacharacters but never strips newlines, and the export layer decodes those entities back before writing iCal output, an attacker with any valid account can craft a subscription whose name breaks out of the current VEVENT block and inserts fully attacker-controlled calendar events — including spoofed organizers, arbitrary email addresses in ATTENDEE properties, and misleading event content — into any calendar application subscribed to that feed. This issue has been patched in version 5.0.0.

Metrics

EPSS Probability
0.17%

6.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
elliteWallos< 5.0.0

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-77353?
Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 5.0.0, Wallos allows authenticated users to inject arbitrary iCalendar properties and events into their exported .ics feed by embedding raw CRLF sequences in subscription names or notes. Because the input validation layer only encodes HTML metacharacters but never strips newlines, and the export layer decodes those entities back before writing iCal output, an attacker with any valid account can craft a subscription whose name breaks out of the current VEVENT block and inserts fully attacker-controlled calendar events — including spoofed organizers, arbitrary email addresses in ATTENDEE properties, and misleading event content — into any calendar application subscribed to that feed. This issue has been patched in version 5.0.0.
How severe is CVE-2026-77353?
CVE-2026-77353 has a CVSS score of 4.6/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-77353?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST