{"id":"CVE-2026-120752","kind":"vulnerability","aliases":["CVE-2026-120752"],"related":[],"title":"PyMuPDF: callout points overflow stack, letting crafted input run code","description":"PyMuPDF 1.25.3 before 2.0 contains a stack-based buffer overflow vulnerability in JM_set_annot_callout_line() that copies a caller-supplied number of callout points into a fixed three-element stack array. Attackers who control the callout argument passed to Page.add_freetext_annot() can supply four or more points to overwrite the stack frame, crashing the process or executing code.","summary":"PyMuPDF 1.25.3 before 2.0 has a stack-based buffer overflow in JM_set_annot_callout_line(), which copies a caller-supplied number of callout points into a fixed three-element array. An attacker who controls the callout argument to Page.add_freetext_annot() can crash the process or execute code.","severity":"high","cvss":7.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["package","pymupdf","python"],"not_affected_if":["no-untrusted-callout-input","pymupdf-2.0-or-later"],"how_to_check":"- Check the installed PyMuPDF version with `pip show PyMuPDF` and look for `1.25.3` or any version before `2.0`.\n- Search code for calls to `Page.add_freetext_annot()` that pass callout points from untrusted input.","fix":"- Move to PyMuPDF `2.0` or later, per the sources.","status":"open","published_at":"2026-11-02T23:17:20+00:00","first_seen_at":"2026-11-02T23:35:57+00:00","triaged_at":"2026-11-02T23:36:36+00:00","updated_at":"2026-11-02T23:36:36+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-02T23:36:36Z","model":"claude-haiku-5-5","output":{"fix":"- Move to PyMuPDF `2.0` or later, per the sources.","reach":"unknown","title":"PyMuPDF: callout points overflow stack, letting crafted input run code","impact":"high","summary":"PyMuPDF 1.25.3 before 2.0 has a stack-based buffer overflow in JM_set_annot_callout_line(), which copies a caller-supplied number of callout points into a fixed three-element array. An attacker who controls the callout argument to Page.add_freetext_annot() can crash the process or execute code.","audience":"developers","category":"package","nicknames":[],"who_cares":["python","pymupdf"],"confidence":0.6,"fix_status":"available","needs_auth":"unknown","worst_case":"code runs in the process that parses the PDF","analyst_note":"Check the patch and release notes at github.com links to confirm the exact fixed version and whether exploitation requires only the callout argument.","how_to_check":"- Check the installed PyMuPDF version with `pip show PyMuPDF` and look for `1.25.3` or any version before `2.0`.\n- Search code for calls to `Page.add_freetext_annot()` that pass callout points from untrusted input.","plain_action":"","needs_analyst":true,"not_affected_if":["no-untrusted-callout-input","pymupdf-2.0-or-later"],"who_is_affected":"Applications that use PyMuPDF 1.25.3 or earlier 2.0 releases to add FreeText annotations with callout lines, especially where the callout points come from user-supplied documents or requests. Code that never passes attacker-controlled callout data to Page.add_freetext_annot() is much less exposed. unknown whether other PyMuPDF call paths are affected.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000739,"input_tokens":4222,"output_tokens":634,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-120752':13A,16A '-2026':12A,15A '1.25.3':21B,73C '2.0':23B,75C 'annot':34B,64B,87C,118C 'argument':60B,113C 'array':53B,107C 'attack':55B,108C 'base':28B,80C 'buffer':29B,81C 'caller':41B,94C 'caller-suppli':40B,93C 'callout':2A,35B,45B,59B,88C,98C,112C 'code':10A,71B,135C 'contain':76C 'control':57B,110C 'copi':38B,91C 'craft':7A 'crash':66B,130C 'cve':11A,14A 'element':52B,105C 'execut':70B,134C 'fix':49B,102C 'four':121C 'frame':129C 'freetext':63B,117C 'input':8A 'jm':32B,85C 'let':6A 'line':36B,89C 'number':43B,96C 'overflow':4A,30B,82C 'overwrit':126C 'packag':17B 'page.add':62B,116C 'pass':114C 'point':3A,46B,99C,124C 'process':68B,132C 'pymupdf':1A,18B,20B,72C 'python':19B 'run':9A 'set':33B,86C 'stack':5A,27B,79C,106C,128C 'stack-bas':26B,78C 'suppli':42B,95C,120C 'three':51B,104C 'three-el':50B,103C 'vulner':83C","nicknames":[],"mitigations":[],"who_affected":"Applications that use PyMuPDF 1.25.3 or earlier 2.0 releases to add FreeText annotations with callout lines, especially where the callout points come from user-supplied documents or requests. Code that never passes attacker-controlled callout data to Page.add_freetext_annot() is much less exposed. unknown whether other PyMuPDF call paths are affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","package","pymupdf","python"],"first_public_at":"2026-11-02T23:17:20+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/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-2026-120752","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120752","severity":null,"published_at":"2026-11-02T23:17:20+00:00","modified_at":"2026-11-02T23:17:20+00:00","first_seen_at":"2026-11-02T23:35:57+00:00","fetched_at":"2026-11-02T23:35:57+00:00","note":null}],"documents":[{"id":54421,"url":"https://github.com/pymupdf/PyMuPDF/commit/d4298ead84ceeae1c9065c81cd9a275a1b092f5e","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":54422,"url":"https://github.com/pymupdf/PyMuPDF/releases/tag/2.0","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":54423,"url":"https://www.vulncheck.com/advisories/pymupdf-1.25.3-before-2.0-stack-buffer-overflow-via-add-freetext-annot-callout","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"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}