CVE-2026-3147 Overview
A heap-based buffer overflow vulnerability has been identified in libvips versions up to 8.18.0. The vulnerability exists in the vips_foreign_load_csv_build function within the file libvips/foreign/csvload.c. This memory corruption flaw occurs when the library fails to properly validate that whitespace and separator parameters are ASCII characters before processing CSV files, allowing an attacker with local access to potentially corrupt heap memory through crafted input.
Critical Impact
Local attackers can exploit this heap-based buffer overflow in libvips CSV loading functionality to potentially cause application crashes, corrupt memory, or achieve code execution through maliciously crafted CSV input with non-ASCII whitespace or separator characters.
Affected Products
- libvips versions up to 8.18.0
- Applications and services that utilize libvips for CSV file processing
- Image processing pipelines integrating libvips library
Discovery Timeline
- 2026-02-25 - CVE-2026-3147 published to NVD
- 2026-02-25 - Last updated in NVD database
Technical Details for CVE-2026-3147
Vulnerability Analysis
This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw resides in the CSV loading component of libvips, specifically within the vips_foreign_load_csv_build function located in libvips/foreign/csvload.c. The vulnerability requires local access to exploit, meaning an attacker needs the ability to provide malicious CSV input to an application utilizing the vulnerable libvips library.
The core issue stems from insufficient validation of user-controllable input parameters before memory operations are performed. When processing CSV files, the library accepts whitespace and separator configuration options that were not properly validated, allowing non-ASCII characters to be processed in ways that corrupt heap memory.
Root Cause
The root cause of CVE-2026-3147 is the absence of ASCII character validation for the whitespace and separator parameters in the CSV loading functionality. Before the patch, the vips_foreign_load_csv_build function would proceed to create string buffers and process CSV data without verifying that these critical parameters contained only ASCII characters. Non-ASCII characters in these fields could lead to unexpected behavior during string parsing operations, resulting in heap memory corruption through out-of-bounds memory access.
Attack Vector
The attack requires local access to the target system or the ability to provide malicious input to an application using libvips. An attacker would craft a malicious CSV file or manipulate the whitespace and separator parameters with non-ASCII characters when invoking libvips CSV loading functions. When the vulnerable application processes this input, the heap-based buffer overflow is triggered, potentially allowing memory corruption, denial of service, or in certain scenarios, code execution.
The exploit methodology has been publicly disclosed, increasing the risk of active exploitation in the wild.
// Patch applied in csvload.c - Source: GitHub Commit b3ab458a
// The fix validates that whitespace and separator are ASCII before processing
int i;
const char *p;
if (!g_str_is_ascii(csv->whitespace) ||
!g_str_is_ascii(csv->separator)) {
vips_error("csvload", "%s",
_("whitespace and separator must be ASCII"));
return -1;
}
if (!(csv->sbuf = vips_sbuf_new_from_source(csv->source)))
return -1;
Source: GitHub Commit b3ab458a25e0e261cbd1788474bbc763f7435780
Detection Methods for CVE-2026-3147
Indicators of Compromise
- Unexpected crashes or segmentation faults in applications using libvips CSV loading functionality
- Anomalous heap memory corruption errors in application logs related to CSV processing
- CSV files with unusual non-ASCII characters in delimiter or whitespace positions
- Increased memory allocation anomalies in libvips-dependent processes
Detection Strategies
- Monitor application logs for errors originating from csvload.c or the vips_foreign_load_csv_build function
- Implement file integrity monitoring for applications utilizing libvips to detect unexpected behavior
- Deploy runtime memory protection mechanisms (ASLR, stack canaries) to detect exploitation attempts
- Utilize static analysis tools to identify libvips version in use across your environment
Monitoring Recommendations
- Enable verbose logging for applications using libvips to capture CSV processing errors
- Implement anomaly detection for unusual CSV file characteristics in upload or processing pipelines
- Monitor system logs for heap corruption indicators or unexpected process terminations
- Track libvips library version deployments across infrastructure for vulnerability management
How to Mitigate CVE-2026-3147
Immediate Actions Required
- Update libvips to a patched version that includes commit b3ab458a25e0e261cbd1788474bbc763f7435780
- Review applications using libvips CSV loading functionality and assess exposure
- Implement input validation at the application layer to ensure CSV parameters contain only ASCII characters
- Consider temporarily disabling CSV loading functionality if not required until patching is complete
Patch Information
A security patch has been released by the libvips development team. The fix is identified by commit hash b3ab458a25e0e261cbd1788474bbc763f7435780. The patch adds validation to ensure that the whitespace and separator parameters are ASCII characters before proceeding with CSV processing operations.
For detailed patch information, refer to:
Workarounds
- Implement application-level input validation to reject non-ASCII characters in whitespace and separator parameters before passing to libvips
- Restrict CSV file uploads to trusted sources only until patching is completed
- Deploy Web Application Firewalls (WAF) or input sanitization layers to filter potentially malicious CSV content
- Consider using containerization with limited privileges for applications processing untrusted CSV files
# Example: Check installed libvips version
vips --version
# Verify the patch is applied by checking git log
cd /path/to/libvips
git log --oneline | grep b3ab458
# Rebuild libvips from patched source
git pull origin master
meson setup build --wipe
meson compile -C build
sudo meson install -C build
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
