GHSA-33h2-69j3-r336 CVE-2017-12598 PYSEC-2026-2805 PYSEC-2026-698

Out-of-bounds Read in OpenCV

High PyPI

Severity: 8.8 / 10; High · CVSS 3.0
Exploit chance (EPSS): 1.99%; Chance of exploitation in the next 30 days. Higher than 80.60% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-125 Out-of-bounds Read
Fix: Available; 2 packages have a fixed version

Description

OpenCV (Open Source Computer Vision Library) through 3.3 (corresponding to OpenCV-Python 3.3.0.9) has an out-of-bounds read error in the cv::RBaseStream::readBlock function in modules/imgcodecs/src/bitstrm.cpp when reading an image file by using cv::imread, as demonstrated by the 8-opencv-invalid-read-fread test case.

Affected versions

PyPI

Package	Vulnerable	Fixed in
opencv-contrib-python	`< 3.3.1.11`	`3.3.1.11`
opencv-python	`< 3.3.1.11`	`3.3.1.11`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

opencv-contrib-python PyPI → `3.3.1.11`

pip

pip install --upgrade "opencv-contrib-python>=3.3.1.11"

poetry

poetry add "opencv-contrib-python>=3.3.1.11"

uv

uv add "opencv-contrib-python>=3.3.1.11"

opencv-python PyPI → `3.3.1.11`

pip

pip install --upgrade "opencv-python>=3.3.1.11"

poetry

poetry add "opencv-python>=3.3.1.11"

uv

uv add "opencv-python>=3.3.1.11"

Severity breakdown

CVSS 3.0 8.8

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-125: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How to prevent it

Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.
Architecture and Design: Use a language that provides appropriate memory abstractions.

References

Advisories

Packages

Timeline

Oct 12, 2021 Published
Sep 10, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
PYSEC-2023-183 opencv-python versions before v4.8.1.78 bundled libwebp binaries in wheels that are vulnerable to CVE-2023-4863.	High Known exploited	Also affects opencv-python
PYSEC-2023-181 opencv-contrib-python versions before v4.8.1.78 bundled libwebp binaries in wheels that are vulnerable to CVE-2023-4863.	High Known exploited	Also affects opencv-contrib-python
GHSA-qr4w-53vh-m672 opencv-python bundled libwebp binaries in wheels that are vulnerable to CVE-2023-4863	High	Also affects opencv-python
GHSA-cxjf-x6jp-p7mc opencv-contrib-python bundled libwebp binaries in wheels that are vulnerable to CVE-2023-4863	High	Also affects opencv-contrib-python
GHSA-9g8h-pjm4-q92p Out-of-bounds Write in OpenCV.	Medium	Also affects opencv-contrib-python
GHSA-q799-q27x-vp7w Out-of-bounds Write in OpenCV	High	Also affects opencv-contrib-python
GHSA-m6vm-8g8v-xfjh Out-of-bounds Write in OpenCV	High	Also affects opencv-contrib-python
GHSA-jggw-2q6g-c3m6 Out-of-bounds Read in OpenCV	Medium	Also affects opencv-contrib-python

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