CVE-2026-77353

MEDIUMPre-NVD 4.64.6—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 94% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
4.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.6Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
4.6
EG Score
4.6(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity46% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

August 31, 2026

Last Modified

September 8, 2026

Advisory Details (2)

Auto-updated Aug 31, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_release.
github_release Patch Available

v5.0.0

Patch available: ellite/Wallos v5.0.0

https://github.com/ellite/Wallos/releases/tag/v5.0.0
github Patch Available🟡 PoC Available

iCalendar Injection via CRLF in Subscription Name/Notes Export · Advisory · ellite/Wallos · GitHub

https://github.com/ellite/Wallos/security/advisories/GHSA-q2r8-m9wm-5547

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 01:06 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 02:55 UTCEG score recompute
  4. 2026-09-17 04:45 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 06:34 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 08:24 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-14 10:14 UTCEG score recompute
  11. 2026-09-13 12:04 UTCEG score recompute
  12. 2026-09-12 15:02 UTCEPSS rescore
  13. 2026-09-11 15:44 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-10 17:32 UTCEG score recompute
  16. 2026-09-10 09:35 UTCEPSS rescore
  17. 2026-09-09 19:22 UTCEG score recompute
  18. 2026-09-08 22:01 UTCEPSS rescore
  19. 2026-09-08 10:03 UTCEG score recompute
  20. 2026-09-07 11:35 UTCEG score recompute
  21. 2026-09-06 13:48 UTCEPSS rescore
  22. 2026-09-06 13:21 UTCEG score recompute
  23. 2026-09-04 17:00 UTCEG score recompute
  24. 2026-09-04 05:07 UTCEPSS rescore
  25. 2026-09-03 18:48 UTCEG score recompute
Show 8 more
  1. 2026-09-03 17:45 UTCEG score recompute
  2. 2026-09-02 20:02 UTCEG score recompute
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 20:31 UTCEG score recompute
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-08-31 22:21 UTCEG score recompute
  7. 2026-08-31 21:30 UTCEG score recompute
  8. 2026-08-31 21:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-77353?
CVE-2026-77353 is a medium vulnerability published on August 31, 2026. 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…
When was CVE-2026-77353 disclosed?
CVE-2026-77353 was first published in the National Vulnerability Database on August 31, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77353 actively exploited?
CVE-2026-77353 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.8% of all scored CVEs.
What is the CVSS score of CVE-2026-77353?
CVE-2026-77353 has a CVSS v3 base score of 4.6 (NVD).
How do I remediate CVE-2026-77353?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77353, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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