AIKIDO-2026-595238
rarfile is vulnerable to Denial of Service (DoS)
75
CVE Score
High
Denial of Service (DoS)
TL;DR
The RAR3 archive parser reads an archive-controlled 32-bit size field for legacy old-style sub-blocks and calls fd.read() with that value before the block header CRC is validated. A crafted archive of under one kilobyte can therefore force the process to allocate a multi-gigabyte bytes object purely while the file is being parsed. Every public entry point that opens an archive, such as RarFile, is_rarfile, extractall, read, and testrar, reaches this path and can exhaust available memory. The fix stops eagerly reading the sub-block payload and bounds the size before any allocation.
How do I fix this?
Upgrade the rarfile library to the patch version.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and your application parses RAR archives from untrusted or externally supplied sources.
Package
Versions
0.0.1 - 4.3.0
Fixed in 4.4.0Background info
rarfile is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 4.3.0.
Get secure today,
quickly and for free.
Secure your code, cloud, and runtime in one central system. Connect a repo to discover what the reasoning agents find in your codebase.
No credit card required | Scan results in 32 seconds.
I consent to receiving marketing communications based on Aikido’s Privacy Policy.
SOC 2Compliant
ISO 27001CompliantISO 42001Compliant
FedRAMPAuthorized© All Intel data is openly available and commercially licensed.