Memory exhaustion via unbounded integer decoding
Published Jul 28, 2026 · Updated Jul 28, 2026
Resource exhaustion in Nine Nines Cowlib 2.0.0-pre.1 through 2.18.0 allows remote attackers to exhaust memory via crafted HPACK or QPACK integers. The cow_hpack_common:dec_big_int/3 decoder accepts unlimited continuation octets and repeatedly builds ever-wider immutable Erlang integers. An unauthenticated peer must reach an endpoint that decodes HPACK or QPACK; one large field triggers substantial transient allocation, and repeated connections can exhaust the Erlang VM.
Summary
What happened
Resource exhaustion in Nine Nines Cowlib 2.0.0-pre.1 through 2.18.0 allows remote attackers to exhaust memory via crafted HPACK or QPACK integers. The cow_hpack_common:dec_big_int/3 decoder accepts unlimited continuation octets and repeatedly builds ever-wider immutable Erlang integers. An unauthenticated peer must reach an endpoint that decodes HPACK or QPACK; one large field triggers substantial transient allocation, and repeated connections can exhaust the Erlang VM.
The record
- CVE
- CVE-2026-59248
- Published
- Jul 28, 2026
- Updated
- Jul 28, 2026
- Vendor
- Nine Nines
- Product
- Cowlib
- Classifications
- CWE-770, CAPEC-130, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 28, 2026CVE publishedPublication date reported by the CVE source.
- Jul 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.0.0-pre.1 <2.19.0
- Affected versionversion=5ddecbc121f812aec53d9df91829448d8e94e44c <f582430498072a0c65ad338030321576dc13a343
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo