CVE-2026-77353
MEDIUMDescription
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 to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
TridentStack Control tracks known vulnerabilities across your Windows, macOS, and Linux fleet and shows the fix as soon as one is published. See how it works
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 6% of all known CVEs.
References
Related Vulnerabilities
Other CWE-74 (Injection) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2013-2251 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2023-22527 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2019-2725 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2022-46169 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2022-35914 | Critical | 9.8 | 100% | KEV | - |
| CVE-2019-17558 | High | 7.5 | 99% | KEV | Fix |
Common questions
How do I fix CVE-2026-77353?
No published fix for CVE-2026-77353 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2026-77353 being actively exploited?
Not that we know of. CVE-2026-77353 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.17% is the estimated probability that it will be exploited in the next 30 days. That is higher than 6% of all scored CVEs.
How severe is CVE-2026-77353?
CVE-2026-77353 has a CVSS v3 base score of 4.6, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
Embed a live status badge for CVE-2026-77353
Markdown
[](https://tridentstack.com/cve/CVE-2026-77353)HTML
<a href="https://tridentstack.com/cve/CVE-2026-77353"><img src="https://tridentstack.com/cve/badge/CVE-2026-77353.svg" alt="CVE-2026-77353"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-08.