Loading vulnerability…
CVE-2025-61770 is a denial-of-service vulnerability in Rack's multipart request handling, specifically in Rack::Multipart::Parser. In affected versions, the parser buffers the entire multipart preamble—the bytes that appear before the first multipart boundary—into memory without enforcing a size limit. A remote attacker can send a crafted multipart/form-data HTTP request containing an excessively large preamble followed by a valid boundary, causing Rack to allocate large amounts of memory while parsing the request. The issue affects Rack versions prior to 2.2.19, 3.1.17, and 3.2.2. The fix introduces a preamble/boundary-start limit (documented as 16 KiB in the patch context, with effective behavior influenced by buffer size) or discards preamble data entirely, preventing unbounded buffering.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
multipart/form-data uploads; constrain per-process memory to reduce blast radius from OOM events; and monitor application memory usage and worker restarts for signs of exploitation. These measures only reduce exploitability and impact; the definitive mitigation is upgrading to a patched Rack version.Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.