CVE-2025-48379 is a high-severity (CVSS 7.1) CWE-122 vulnerability in pillow. A fix is available for pillow — see the affected versions and patch details below.
Pillow Vulnerable to Write Buffer Overflow on BCn encoding
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-48379.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
pillowReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
There is a heap buffer overflow when writing a sufficiently large (>64k encoded with default settings) image in the DDS format due to writing into a buffer without checking for available space.
This only affects users who save untrusted data as a compressed DDS image.
- Unclear how large the potential write could be. It is likely limited by process segfault, so it's not necessarily deterministic. It may be practically unbounded.
- Unclear if there's a restriction on the bytes that could be emitted. It's likely that the only restriction is that the bytes would be emitted in chunks of 8 or 16.
This was introduced in Pillow 11.2.0 when the feature was added.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pillow | ≥ 11.2.0&&< 11.3.0 | 11.3.0pip install --upgrade 'pillow==11.3.0' |
Affected Products
pillowpythonDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pillow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pillow to 11.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48379 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability was rated as Important by the Red Hat Product Security Engineer. An attacker may leverage that by crafting a malicious DDS image bigger than 64k (when encoded). This happens because of the lack of size checking when writing the image data into an internal buffer. When successfully exploited, this…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2025-48379 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux AI 1.5 | rhelai1/instructlab-nvidia-rhel9:1.5.3-1756791365 | RHSA-2025:15832 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-intel-rhel9:1.5.3-1756724193 | RHSA-2025:15836 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-gcp-nvidia-rhel9:1.5.3-1756815294 | RHSA-2025:15837 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-aws-nvidia-rhel9:1.5.3-1756815228 | RHSA-2025:15838 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-amd-rhel9:1.5.3-1756800437 | RHSA-2025:15839 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-azure-amd-rhel9:1.5.3-1756815221 | RHSA-2025:15840 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-nvidia-rhel9:1.5.3-1756799326 | RHSA-2025:15841 |
| Red Hat Enterprise Linux AI 1.5 | rhelai1/bootc-azure-nvidia-rhel9:1.5.3-1756815370 | RHSA-2025:15842 |
Frequently Asked Questions
Is CVE-2025-48379 in your dependencies?
Find it across PyPI, including transitive dependencies.