Heap memory corruption via wrapped composition offsets
Published May 19, 2026 · Updated May 19, 2026
Heap buffer over-read and write in Kovid Goyal kitty 0.46.2 and earlier allows remote attackers to corrupt memory via terminal output. handle_compose_command() adds attacker-controlled composition offsets and dimensions with unsigned 32-bit arithmetic, letting wrapped sums pass bounds checks before compose_rectangles() uses the original offsets in heap pointer calculations. Any source able to emit escape sequences into a default kitty window can trigger a crash, out-of-bounds read, or attacker-influenced out-of-bounds write without further interaction.
Summary
What happened
Heap buffer over-read and write in Kovid Goyal kitty 0.46.2 and earlier allows remote attackers to corrupt memory via terminal output. handle_compose_command() adds attacker-controlled composition offsets and dimensions with unsigned 32-bit arithmetic, letting wrapped sums pass bounds checks before compose_rectangles() uses the original offsets in heap pointer calculations. Any source able to emit escape sequences into a default kitty window can trigger a crash, out-of-bounds read, or attacker-influenced out-of-bounds write without further interaction.
The record
- CVE
- CVE-2026-33642
- Published
- May 19, 2026
- Updated
- May 19, 2026
- Vendor
- Kovid Goyal
- Product
- kitty
- Classifications
- CWE-125, CWE-787, CWE-190, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 19, 2026CVE publishedPublication date reported by the CVE source.
- May 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.47.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- poc_compose_oob.pyproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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