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Fencer Vulns
critical 9.9

CVE-2026-33642 json

Kitty has a Heap Buffer Over-Read/Write via Integer Overflow in compose_rectangles Bounds Check

published 2026-05-19 5 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-30968

cvss
9.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits
0
none known

Summary

Kitty is a cross-platform GPU based terminal. In versions 0.46.2 and below, the handle_compose_command() function in kitty/graphics.c performs bounds validation on composition offsets using unsigned 32-bit arithmetic that is subject to integer wrapping, potentially leading to Heap Buffer Over-Read/Write. An attacker who can write escape sequences to a kitty terminal (e.g., via a malicious file, SSH login banner, or piped content) can supply crafted x_offset/y_offset values that pass the bounds check after wrapping but cause massive out-of-bounds heap memory access in compose_rectangles(). No user interaction is required. No non-default configuration is required. The attacker only needs the ability to produce output in a kitty terminal window. This issue has been fixed in version 0.47.0.

Patch / fix

  • kitty_project kitty 0.47.0
  • kovidgoyal kitty 0.47.0
  • kitty Debian 13 0.41.1-2+deb13u1
  • kitty Debian 14 0.47.0-1

debian advisories DEBIAN-CVE-2026-33642

  • kitty Ubuntu 25.10 0.41.1-2+deb13u1build0.25.10.1
  • kitty Ubuntu Pro 20.04 LTS 0.15.0-1ubuntu0.2+esm1
  • kitty Ubuntu Pro 22.04 LTS 0.21.2-1ubuntu0.22.04.1+esm1
  • kitty Ubuntu Pro 24.04 LTS 0.32.2-1ubuntu0.4+esm1
  • kitty Ubuntu Pro 26.04 LTS 0.45.0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2026-33642

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kitty openSUSE Leap 16.0 0.48.2-bp160.1.1

opensuse advisories openSUSE-SU-2026:21599-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-33642 updated cvss 10.0

kitty: Kitty: Arbitrary Code Execution via Integer Wrapping in Escape Sequence Handling

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/kovidgoyal/kitty/security/advisories/GHSA-qfgm-2c64-6x3x referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • kovidgoyal kitty

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.