CVE-2026-80431
- Source
- https://cve.org/CVERecord?id=CVE-2026-80431
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80431.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-80431
- Downstream
- Published
- 2026-09-25T13:23:51Z
- Modified
- 2026-09-27T08:04:16Z
- Severity
-
- 6.8 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Out-of-bounds write in the kitty text sizing protocol allows termination of the terminal process
- Details
-
Out-of-bounds Write in the natural width branch of the text sizing protocol in kitty from 0.40.0 before 0.49.0 allows a program writing to the terminal to write past the end of a fixed-size buffer, because screen_handle_multicell_command() in kitty/screen.c appends each codepoint of a grapheme cluster with lc.chars[lc.count++] = ch without any capacity check, while lc is declared by the RAII_ListOfChars macro as a four-element char_type array in the function's stack frame, so an OSC 66 escape code whose payload carries a grapheme cluster longer than four codepoints writes beyond that buffer, one 32-bit value per additional codepoint, in the order the codepoints appear. Where the cluster is preceded in the same payload by a sequence that causes an intermediate flush, the buffer is first migrated to the heap by ensure_space_for_chars() and the write occurs past the heap allocation instead. This results in termination of the kitty process and therefore of all its windows, tabs and child processes.
- Database specific
{ "cna_assigner": "Secur0", "cwe_ids": [ "CWE-787" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80431.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "0.40.0" }, { "fixed": "0.49.0" } ], "source": "AFFECTED_FIELD" }, { "extracted_events": [ { "introduced": "0.40.0" }, { "fixed": "0.49.0" } ], "source": "CPE_FIELD" }, { "extracted_events": [ { "introduced": "0.40.0" }, { "fixed": "0.49.0" } ], "source": "DESCRIPTION" } ] }- References
-
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80431.json
- https://github.com/kovidgoyal/kitty/releases/tag/v0.49.0
- https://nvd.nist.gov/vuln/detail/CVE-2026-80431
- https://secur0.com/en/cna/cve-list/cve-2026-80431-kitty-text-sizing-out-of-bounds-write
- https://github.com/kovidgoyal/kitty/commit/7d2fbaadcc2b1eeeef89bd875ec622b42362574b
- https://github.com/kovidgoyal/kitty
Affected packages
Git / github.com/kovidgoyal/kitty
Affected versions
Other
v0.*
Database specific
source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80431.json"
vanir_signatures
[
{
"deprecated": false,
"digest": {
"function_hash": "124675723751343412283227646228436901329",
"length": 1562
},
"id": "CVE-2026-80431-2a9b4afe",
"signature_type": "Function",
"signature_version": "v1",
"source": "https://github.com/kovidgoyal/kitty/commit/7d2fbaadcc2b1eeeef89bd875ec622b42362574b",
"target": {
"file": "kitty/screen.c",
"function": "screen_handle_multicell_command"
}
},
{
"deprecated": false,
"digest": {
"line_hashes": [
"72792286790462330004774758914164571098",
"579768602607796312266109759146632207",
"288408673375767561784981786624140652804",
"59759986667114008691276290081129616936",
"203876779650048597572406135475748490132"
],
"threshold": 0.9
},
"id": "CVE-2026-80431-8678572d",
"signature_type": "Line",
"signature_version": "v1",
"source": "https://github.com/kovidgoyal/kitty/commit/7d2fbaadcc2b1eeeef89bd875ec622b42362574b",
"target": {
"file": "kitty/screen.c"
}
}
]
vanir_signatures_modified
"2026-09-27T08:04:16Z"