https://vulnerability.circl.lu/sightings/feed 2026-09-02T07:20:02.837520+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent sightings. https://vulnerability.circl.lu/sighting/dd5c7197-9714-48fc-a460-200e89c829b3/export 2026-09-02T07:20:02.867797+00:00 Automation user https://vulnerability.circl.lu/user/automation {"uuid": "dd5c7197-9714-48fc-a460-200e89c829b3", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-55099", "type": "seen", "source": "https://bsky.app/profile/thehackerwire.bsky.social/post/3mtybwck7lt2b", "content": "\ud83d\udfe0 CVE-2026-55099 - High (7.5)\n\nicalendar is an RFC 5545 compatible parser and generator of iCalendar files for Python. From 7.1....\n\nhttps://www.thehackerwire.com/vulnerability/CVE-2026-55099/\n\n#infosec #cybersecurity #CVE #vulnerability #security #patchstack", "creation_timestamp": "2026-08-26T12:00:53.203137Z"} 2026-08-26T12:00:53.203137+00:00 https://vulnerability.circl.lu/sighting/224ef8e5-94e1-40bc-8684-3911e656b54b/export 2026-09-02T07:20:02.872224+00:00 Automation user https://vulnerability.circl.lu/user/automation {"uuid": "224ef8e5-94e1-40bc-8684-3911e656b54b", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-55099", "type": "seen", "source": "https://gist.github.com/alon710/c546d90432dcc6f5c367a6df4e89153b", "content": "# CVE-2026-55099: CVE-2026-55099: Algorithmic Complexity Denial of Service in icalendar Component Equality\n\n> **CVSS Score:** 7.5\n> **Published:** 2026-08-25\n> **Full Report:** https://cvereports.com/reports/CVE-2026-55099\n\n## Summary\nAn algorithmic complexity denial of service vulnerability exists in the Python icalendar library's component equality evaluation. Due to recursive nested comparisons inside list membership operations, parsing and validating calendar components with deep nesting triggers exponential execution time, blocking application threads and consuming 100% of the available CPU core.\n\n## TL;DR\nAn exponential time complexity issue in icalendar's comparison logic allows unauthenticated remote attackers to cause Denial of Service by submitting deeply nested, lightweight calendar payloads.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-407\n- **Attack Vector**: Network\n- **Complexity**: Low\n- **CVSS v3.1 Score**: 7.5 (High)\n- **Impact**: Denial of Service (Thread Exhaustion)\n- **Exploit Status**: PoC Available\n\n## Affected Systems\n\n- icalendar (Python library)\n- **icalendar**: >= 7.1.0, < 7.1.3 (Fixed in: `7.1.3`)\n\n## Mitigation\n\n- Upgrade to icalendar version 7.1.3 or higher\n- Implement strict validation of input nesting depth prior to parsing\n\n**Remediation Steps:**\n1. Update pip environments using pip install --upgrade icalendar\n2. Add pre-parser checks to block deeply nested VEVENT elements\n3. Restart calendar synchronizers to apply changes\n\n## References\n\n- [GitHub Security Advisory](https://github.com/collective/icalendar/security/advisories/GHSA-cv84-9p8j-fj68)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/CVE-2026-55099) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-08-25T21:34:19.073981Z"} 2026-08-25T21:34:19.073981+00:00 https://vulnerability.circl.lu/sighting/6dc07744-5ca2-49e4-9ff1-da4920dbe30c/export 2026-09-02T07:20:02.872392+00:00 Joseph Lee https://vulnerability.circl.lu/user/syspect {"uuid": "6dc07744-5ca2-49e4-9ff1-da4920dbe30c", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-55099", "type": "published-proof-of-concept", "source": "https://github.com/collective/icalendar/security/advisories/GHSA-cv84-9p8j-fj68", "content": "", "creation_timestamp": "2026-08-25T20:35:03.349916Z"} 2026-08-25T20:35:03.349916+00:00 https://vulnerability.circl.lu/sighting/626f656f-eec2-4260-a333-2a6f7867c385/export 2026-09-02T07:20:02.873488+00:00 Automation user https://vulnerability.circl.lu/user/automation {"uuid": "626f656f-eec2-4260-a333-2a6f7867c385", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-55099", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/ihcp4kg62x6wh", "content": "CVE-2026-55099 - icalendar: Algorithmic Complexity in Equality\nCVE ID : CVE-2026-55099\n \n Published : Aug. 25, 2026, 7:27 p.m. | 39\u00a0minutes ago\n \n Description : icalendar is an RFC 5545 compatible parser and generator of iCalendar files for Python. From 7.1.0 until 7.1.3, the ...", "creation_timestamp": "2026-08-25T20:19:50.317062Z"} 2026-08-25T20:19:50.317062+00:00 https://vulnerability.circl.lu/sighting/28bd378f-ad9f-4f32-b012-4f27d0d99cd0/export 2026-09-02T07:20:02.873614+00:00 Automation user https://vulnerability.circl.lu/user/automation {"uuid": "28bd378f-ad9f-4f32-b012-4f27d0d99cd0", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-55099", "type": "seen", "source": "https://bsky.app/profile/infosec.skyfleet.blue/post/3moyarz35ep24", "content": "icalendar: Denial of Service CVE-2026-55099", "creation_timestamp": "2026-06-23T20:34:36.861111Z"} 2026-06-23T20:34:36.861111+00:00