PyMuPDF 1.25.3 before 2.0 contains a stack-based buffer overflow vulnerability in JM_set_annot_callout_line() that
Affects pymupdfSource GCVE Database
Not known to be exploited · CVSS 7.7 High : upgrade to 2.0 soon.
Data as of 3 Nov 2026, 01:29 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 7.7 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.5 |
- Patch
- Available – fixed in 2.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 2 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
Upgrade pymupdf to 2.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIpymupdfpkg:pypi/pymupdfOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, avoid processing untrusted input that uses the Page.add_freetext_annot() function with callout points.
Description
PyMuPDF versions before 2.0, including 1.25.3, have a stack-based buffer overflow vulnerability in the JM_set_annot_callout_line() function. This flaw occurs because the function copies a caller-supplied number of callout points into a fixed-size three-element stack array without proper bounds checking. An attacker controlling the callout argument passed to Page.add_freetext_annot() can supply four or more points, potentially overwriting the stack frame, leading to process crashes or arbitrary code execution.
References
- nvd.nist.gov/vuln/detail/CVE-2026-120752 (opens in a new tab)
- github.com/pymupdf/PyMuPDF/issues/5112 (opens in a new tab)
- github.com/pymupdf/PyMuPDF/issues/5173 (opens in a new tab)
- github.com/pymupdf/PyMuPDF/commit/d4298ead84ceeae1c9065c81cd9a275a1b092f5e (opens in a new tab)
- github.com/pymupdf/PyMuPDF (opens in a new tab)
- github.com/pymupdf/PyMuPDF/blob/1.28.2/src/extra.i (opens in a new tab)
- github.com/pymupdf/PyMuPDF/releases/tag/2.0 (opens in a new tab)
- vulncheck.com/advisories/pymupdf-1.25.3-before-2.0-stack-buffer-overflow-via-add-freetext-annot-callout (opens in a new tab)