Summary
Workarounds
Avoid Pillow >= 10.3.0, < 12.2.0
Only open specific image formats, excluding FITS.
Impact
Pillow did not limit the amount of GZIP-compressed data read when decoding a FITS image, making it vulnerable to decompression bomb attacks. A specially crafted FITS file could cause unbounded memory consumption, leading to denial of service (OOM crash or severe performance degradation).
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2026-40192 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (12.2.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
The amount of data read is now limited to the necessary amount.
Fixed in Pillow 12.2.0 (PR #9521).
Frequently Asked Questions
- What is CVE-2026-40192? CVE-2026-40192 is a high-severity uncontrolled resource consumption vulnerability in pillow (pip), affecting versions >= 10.3.0, < 12.2.0. It is fixed in 12.2.0. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2026-40192? CVE-2026-40192 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pillow are affected by CVE-2026-40192? pillow (pip) versions >= 10.3.0, < 12.2.0 is affected.
- Is there a fix for CVE-2026-40192? Yes. CVE-2026-40192 is fixed in 12.2.0. Upgrade to this version or later.
- Is CVE-2026-40192 exploitable, and should I be worried? Whether CVE-2026-40192 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-40192 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-40192? Upgrade
pillowto 12.2.0 or later.