Heap out-of-bounds read in libical iCalendar parsing
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.
Summary
libical through 4.0.6 contains a heap-based out-of-bounds read in icalvalue_decode_ical_string() when it decodes input ending in a backslash. A local attacker who can supply escaped iCalendar text, with a user's interaction, can crash the application or leak adjacent heap memory (CWE-125).
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
libical through 4.0.6 contains a heap-based out-of-bounds read in icalvalue_decode_ical_string() in src/libical/icalvalue.c when decoding input ending in a backslash. Attackers can supply escaped iCalendar text with a trailing backslash, causing the loop to read past the terminator and crash the application or leak adjacent heap memory.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
The sources list no fixed version for libical. Red Hat rates this Moderate and lists Red Hat Enterprise Linux 6 (no fix planned), and Red Hat Enterprise Linux 7, 8, 9 and 10 (none available), as affected without a fix.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-16 Threatist record created from CVE-2026-111269
- 2026-10-16 Priority changed: MEDIUM → LOW
- 2026-10-16 Affected versions changed · Red Hat
- 2026-10-16 CVSS score added · Red Hat
- 2026-10-26 CISA SSVC decision points changed
- 2026-10-26 Priority changed: LOW → MEDIUM
References
Patch 2
Sources
- CVE-2026-111269 · CVE Program
- CVE-2026-111269 · NVD
- FIRST EPSS
- CVE-2026-111269 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences