Description
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.
References7
- github.com/libical/libical
- github.com/libical/libical/blob/9cfca65c122fa23b9680a28e0c9225a…
- github.com/libical/libical/commit/d753885ce2de7c105d6b8c405aa7a…
- github.com/libical/libical/pull/1455
- hackmd.io/@haind-pwn/libical-icalvalue-decode-ical-string-oob-r…
- www.vulncheck.com/advisories/libical-through-4.0.6-heap-out-of-…
- hackmd.io/@haind-pwn/libical-icalvalue-decode-ical-string-oob-r…
Metrics
- CVSS 3.1
-
6.1
MEDIUM
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H - CVSS 4.0
-
6.9
MEDIUM
Score source: CNA
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 16 · as of 10 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
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