CVE-2026-43970Network attack vector

Unauthenticated service crash via unbounded SPDY decompression

Published May 13, 2026 · Updated May 13, 2026

Data amplification in Nine Nines Cowlib 0.1.0 through 2.16.0 allows remote attackers to crash the BEAM node via a crafted SPDY frame. cow_spdy:inflate/2 passes peer-supplied compressed bytes to zlib:inflate/2 without an output bound, letting kilobytes expand to gigabytes on the BEAM heap. Exposure requires direct use of cow_spdy:parse/2 on untrusted SPDY frames; Cowboy does not call this API, and successful exhaustion OOM-kills the node.

CVSS severity8.2
High
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Data amplification in Nine Nines Cowlib 0.1.0 through 2.16.0 allows remote attackers to crash the BEAM node via a crafted SPDY frame. cow_spdy:inflate/2 passes peer-supplied compressed bytes to zlib:inflate/2 without an output bound, letting kilobytes expand to gigabytes on the BEAM heap. Exposure requires direct use of cow_spdy:parse/2 on untrusted SPDY frames; Cowboy does not call this API, and successful exhaustion OOM-kills the node.

The record

CVE
CVE-2026-43970
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Nine Nines
Product
Cowlib
Classifications
CWE-409, CAPEC-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.1.0 <2.16.1
  2. Affected versionversion=fad5c0049df278cc498b6cdb519b09e845a070a8 <16aad3fb9f81f5cda4d1706ff0c54237c619c282

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nine Nines · Cowlibversion=0.1.0 <2.16.1; version=fad5c0049df278cc498b6cdb519b09e845a070a8 <16aad3fb9f81f5cda4d1706ff0c54237c619c282

Published CVSS scores

8.2Erlang Ecosystem Foundation CNACVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
CAPEC-130Excessive Allocation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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