Vulnerability in Iterm2
CVE-2026-41253
In iTerm2 through 3.6.9, displaying a .txt file can cause code execution via DCS 2000p and OSC 135 data, if the working directory contains a malicious file whose name is valid output from the conductor encoding path, such as a pathname with an initial ace/c+ substring, aka "hypothetical in-band signaling abuse." This occurs because iTerm2 accepts the SSH conductor protocol from terminal output that does not originate from a legitimate conductor session.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L.
EPSS exploit prediction
EPSS: 0.002 (8.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Iterm2 — versions 0
Weakness classification (CWE)
References
- iterm2.com/downloads.html (Product)
- blog.calif.io/p/mad-bugs-even-cat-readmetxt-is-not (Exploit, Third Party Advisory)
- github.com/gnachman/iTerm2/commit/a9e745993c2e2cbb30b884a16617cd5495899f86 (Patch)
- news.ycombinator.com/item (Issue Tracking)
Frequently asked questions
- What is CVE-2026-41253?
- CVE-2026-41253 is a medium-severity vulnerability in Iterm2, classified under Inclusion of Functionality from Untrusted Control Sphere. CVSS score: 6.9/10. Published 2026-04-18.
- How severe is CVE-2026-41253?
- Medium severity. CVSS v3 base score is 6.9 out of 10.