Bug 2477254 (CVE-2026-43970) - CVE-2026-43970 cowlib: cowlib: Remote denial of service via data amplification in SPDY frame processing
Summary: CVE-2026-43970 cowlib: cowlib: Remote denial of service via data amplificatio...
Keywords:
Status: NEW
Alias: CVE-2026-43970
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2479811
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-13 20:02 UTC by OSIDB Bzimport
Modified: 2026-05-19 11:59 UTC (History)
0 users

Fixed In Version:
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Description OSIDB Bzimport 2026-05-13 20:02:48 UTC 
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows unauthenticated remote denial of service via memory exhaustion.

cow_spdy:inflate/2 in cowlib passes peer-supplied compressed bytes directly to zlib:inflate/2 with no output size bound. The SPDY header compression dictionary (?ZDICT) is public, and zlib compresses long runs of repeated bytes at roughly 1024:1, so a few kilobytes of SPDY frame payload can decompress to gigabytes on the BEAM heap, OOM-killing the node. A single unauthenticated SPDY frame is sufficient to trigger the condition. The parsers for syn_stream, syn_reply, and headers frame types are all affected via cow_spdy:parse_headers/2.

This issue affects cowlib from 0.1.0 before 2.16.1.
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