{"id":"CVE-2026-122136","kind":"vulnerability","aliases":["CVE-2026-122136"],"related":[],"title":"Powerlevel10k: predictable temp file lets local users overwrite victim files","description":"Powerlevel10k before 1.20.19 contains a symlink following vulnerability in _p9k_dump_instant_prompt that allows local attackers to overwrite victim-writable files via a predictable temporary path. Attackers can pre-plant symlinks at p10k-instant-prompt-output-<user>-<pid> in TMPDIR, guessing the victim's shell PID, so shell startup truncates and overwrites targeted files.","summary":"Powerlevel10k, a Zsh prompt theme, writes its instant-prompt cache to a predictable path in TMPDIR and follows symlinks there. A local attacker who pre-plants a symlink can make shell startup truncate and overwrite files the victim can write.","severity":"medium","cvss":4.4,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["multi-user","package","powerlevel10k","shell","zsh"],"not_affected_if":["private-tmpdir","single-user-machine","version-1.20.19-or-later"],"how_to_check":"- Check the installed version with `p10k version` or the theme's git tag where it was cloned.\n- Look for `p10k-instant-prompt-` files in TMPDIR that are symlinks, using `ls -l $TMPDIR`.","fix":"- Powerlevel10k `1.20.19` (fixed version per the advisory; affected: before `1.20.19`).","status":"open","published_at":"2026-11-04T21:18:09+00:00","first_seen_at":"2026-11-04T21:49:20+00:00","triaged_at":"2026-11-04T21:51:30+00:00","updated_at":"2026-11-04T21:51:30+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-04T21:51:30Z","model":"claude-haiku-5-5","output":{"fix":"- Powerlevel10k `1.20.19` (fixed version per the advisory; affected: before `1.20.19`).","reach":"local","title":"Powerlevel10k: predictable temp file lets local users overwrite victim files","impact":"medium","summary":"Powerlevel10k, a Zsh prompt theme, writes its instant-prompt cache to a predictable path in TMPDIR and follows symlinks there. A local attacker who pre-plants a symlink can make shell startup truncate and overwrite files the victim can write.","audience":"developers","category":"package","nicknames":[],"who_cares":["powerlevel10k","zsh","shell","multi-user"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"local user overwrites files the victim can write","analyst_note":"","how_to_check":"- Check the installed version with `p10k version` or the theme's git tag where it was cloned.\n- Look for `p10k-instant-prompt-` files in TMPDIR that are symlinks, using `ls -l $TMPDIR`.","plain_action":"","needs_analyst":false,"not_affected_if":["single-user-machine","private-tmpdir","version-1.20.19-or-later"],"who_is_affected":"Affects people who run Powerlevel10k as their Zsh prompt on a shared or multi-user machine where another local user could write to TMPDIR. Single-user machines with a private TMPDIR carry much lower risk. unknown on whether managed systems or containers are affected.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"medium"},"cost_usd":0.0007,"input_tokens":4214,"output_tokens":558,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-122136':13A,16A '-2026':12A,15A '1.20.19':68C 'allow':80C 'attack':47B,82C,94C 'cach':34B 'contain':69C 'cve':11A,14A 'dump':76C 'file':4A,10A,61B,88C,121C 'follow':42B,72C 'guess':108C 'instant':32B,77C,103C 'instant-prompt':31B 'let':5A 'local':6A,46B,81C 'make':55B 'multi':18B 'multi-us':17B 'output':105C 'overwrit':8A,60B,84C,119C 'p10k':102C 'p10k-instant-prompt-output':101C 'p9k':75C 'packag':20B 'path':38B,93C 'pid':113C 'plant':51B,98C 'powerlevel10k':1A,21B,24B,66C 'pre':50B,97C 'pre-plant':49B,96C 'predict':2A,37B,91C 'prompt':27B,33B,78C,104C 'shell':22B,56B,112C,115C 'startup':57B,116C 'symlink':43B,53B,71C,99C 'target':120C 'temp':3A 'temporari':92C 'theme':28B 'tmpdir':40B,107C 'truncat':58B,117C 'user':7A,19B 'via':89C 'victim':9A,63B,86C,110C 'victim-writ':85C 'vulner':73C 'writabl':87C 'write':29B,65B 'zsh':23B,26B","nicknames":[],"mitigations":[],"who_affected":"Affects people who run Powerlevel10k as their Zsh prompt on a shared or multi-user machine where another local user could write to TMPDIR. Single-user machines with a private TMPDIR carry much lower risk. unknown on whether managed systems or containers are affected.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["medium","multiuser","package","powerlevel10k","shell","zsh"],"campaign_type":null,"first_public_at":"2026-11-04T21:18:09+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-122136","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-122136","severity":null,"published_at":"2026-11-04T21:18:09+00:00","modified_at":"2026-11-04T21:18:09+00:00","first_seen_at":"2026-11-04T21:49:20+00:00","fetched_at":"2026-11-04T21:49:20+00:00","note":null}],"documents":[{"id":70671,"url":"https://github.com/romkatv/powerlevel10k/commit/7ddd1b2715c3844275214347a3572ac1fdd6dc39","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":70672,"url":"https://www.vulncheck.com/advisories/powerlevel10k-before-1.20.19-symlink-following-via-instant-prompt-temporary-file","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"exploit_sources":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}