CVE-2026-54055 — Kitty has an Arbitrary File Write via Symlink Race Condition in File Transmission Protocol
Kitty is a cross-platform GPU based terminal. In versions prior to 0.47.2, a local privilege escalation vulnerability exists in kitty's file transmission protocol where a child process running in the terminal can write to arbitrary files on the filesystem by exploiting a TOCTOU (Time-of-Check-Time-of-Use) race condition between symlink validation and file creation. The `os.open()` call used to create files does not use `O_NOFOLLOW`, allowing an attacker to create a symlink between the initial stat check and the actual file open, causing the write to follow the symlink to an arbitrary destination. Version 0.47.2 fixes the issue.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented mitigation — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Kovidgoyal Kitty).
- Apply the documented mitigations until a definitive fix is available.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Kovidgoyal | Kitty | < 0.47.2 | Vulnerable | NIST National Vulnerability Database |
| Kovidgoyal | Kitty | version < 0.47.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.0 | CVSS 3.1 | Medium | 0.8 | 4.2 | security-advisories@github.com via NIST National Vulnerability Database |
| 5.0 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:L (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.10%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Monitor file creation in web directories and paths with traversal sequences (../).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · kovidgoyal/kitty
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.0
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-54056 Kitty has an arbitrary file overwrite via symlink following in `kitten dnd` remote drop staging Jun 12, 2026
- High CVE-2026-54057 Kitty vulnerable to command injection via unsanitized OSC 21 query reply Jun 12, 2026
- High CVE-2026-42850 Kitty has a shell command injection Jun 12, 2026
- High CVE-2026-42851 @kitty-edit DCS + --color=geninclude vulnerable to Unauthenticated in-process RCE Jun 12, 2026
- Critical CVE-2026-33642 Kitty has a Heap Buffer Over-Read/Write via Integer Overflow in compose_rectangles Bounds Check May 19, 2026
- High CVE-2026-33633 Kitty has a Heap Buffer Overflow in its Graphics Protocol Handler May 19, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-54055 is "Kitty has an Arbitrary File Write via Symlink Race Condition in File Transmission Protocol", rated Medium. It affects Kitty (Kovidgoyal); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.0 describes technical severity. EPSS 0.10% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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