Security Digest · Vulnerability record
CVE-2026-53873: PickleScan's profile.run blocklist mismatch allows exec() bypass
picklescan before 1.0.4 contains an incomplete blocklist for the profile module that fails to block the module-level profile.run() function, allowing attackers to achieve arbitrary code execution via exec().
CVSS 9.3 Critical EPSS 0.7% · p51
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.7%, percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
picklescan(PyPI) < 1.0.4, fixed in 1.0.4. Check your lockfile, including transitive dependencies.
What it is
picklescan before 1.0.4 contains an incomplete blocklist for the profile module that fails to block the module-level profile.run() function, allowing attackers to achieve arbitrary code execution via exec(). Attackers can craft malicious pickle files calling profile.run(statement) to execute arbitrary Python code while picklescan reports zero security issues.
From the GitHub advisory
Summary
picklescan v1.0.3 blocks profile.Profile.run and profile.Profile.runctx but does NOT block the module-level profile.run() function. A malicious pickle calling profile.run(statement) achieves arbitrary code execution via exec() while picklescan reports 0 issues. This is because the blocklist entry "Profile.run" does not match the pickle global name "run".
Severity
High — Direct code execution via exec() with zero scanner detection.
Affected Versions
Weakness type: CWE-184, CWE-697.
Product: picklescan (PyPI) · Assigned by: VulnCheck · Published: 2026-06-17
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | picklescan | < 1.0.4 | 1.0.4 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| picklescan | picklescan | < 1.0.4 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheck | 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| VulnCheck | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.67% probability of exploitation activity in the next 30 days; percentile 51.
Timeline
- — GitHub-reviewed advisory GHSA-7wx9-6375-f5wh published (critical)
- — CVE record last updated
- — CVE record published by VulnCheck
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- GHSA Advisory GHSA-7wx9-6375-f5wh github.com
Vulnerability records
- GitHub Advisory GHSA-7wx9-6375-f5wh github.com
- CVE.org record CVE-2026-53873 cve.org
- NVD entry CVE-2026-53873 nvd.nist.gov