iTerm2 CVE-2026-88514

Requires a local, unprivileged account on the same macOS host (PR:L) - there is no remote vector. The victim must trigger iTerm2's mono-server session restoration so the client calls iTermFileDescriptorClientConnect() against a socket in the world-writable, sticky P_tmpdir (/var/tmp). The attacker must pre-create a socket with the predictable name iTerm2.socket.<pid> before the client connects and win the TOCTOU race (including predicting the child pid), then pass an attacker-controlled pty master via SCM_RIGHTS. Limiting factors that reduce realistic risk: a local account is mandatory, session restoration must occur, the pid is predictable-but-not-known in advance, the exploit is a timing race (unreliable), and it affects only iTerm2 versions before 3.6.12; the patched client rejects any peer whose euid differs from the user's.

This is a medium-severity, locally-exploitable information-disclosure flaw (CVSS 5.5, CWE-200) that is a low-to-moderate real-world priority rather than an urgent one. All low-urgency signals align: the CVSS vector is AV:L/PR:L (an authenticated local user on the same macOS host, not remote), and CISA's SSVC decision framework rates Exploitation: none, Automatable: no, Technical Impact: partial - i.e. no observed exploitation and not mass-automatable. No KEV listing and no EPSS score are present in the input, consistent with a non-widespread, targeted-access issue. The main conflict is attack complexity: the input vector asserts AC:L, but the commit evidence shows the attack is a TOCTOU socket-squatting race in world-writable /var/tmp against a predictable-but-unknown name (iTerm2.socket.<pid>) that also depends on the victim triggering session restoration - mechanics that argue for AC:H and lower reliability than AC:L implies; verify complexity against the mechanism. Data quality is weak: the CPE (cpe:2.3:a:n/a:n/a) and EUVD affected versions ('n/a n/a') are placeholders, so only the description anchors the <3.6.12 boundary. A gist is referenced and may be a PoC/writeup, but no working exploit is confirmed in structured data. Net: real but gated by local access and a race - prioritize for shared/multi-user Macs, deprioritize for single-user workstations.

On a shared or multi-user macOS host, a low-privileged local user pre-creates a UNIX socket at /var/tmp/iTerm2.socket.<pid> before the victim's iTerm2 launches. When the victim starts iTerm2 and a session is restored, the client connects to the attacker's squatted socket, and the attacker hands over an attacker-controlled pty master via SCM_RIGHTS, man-in-the-middling the restored terminal and capturing its contents. A referenced gist (NSEcho) may contain proof-of-concept or writeup material, but no exploit is confirmed in CISA KEV; exploitation is local (AV:L) and gated by a timing race.