curl Unbounded WebSocket PING Memory Exhaustion
CVE-2026-11586 Published on July 3, 2026
WS Auto-PONG memory exhaustion
By default, curl automatically responds to WebSocket PING frames. Because curl
lacks an upper bound on memory allocation for unacknowledged frames, a
malicious server can exhaust all available memory by flooding curl with rapid,
sequential PING messages.
Vulnerability Analysis
CVE-2026-11586 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.
Products Associated with CVE-2026-11586
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Affected Versions
curl:- Version 8.16.0 and below 8.16.1 is affected.
- Version 8.17.0 and below 8.20.1 is affected.
- Version 0b091328773c64e23f5c4739da74527093c6a5ab and below 849317ff5c5a5e13f50ec3d001e46ddffa77d8a4 is affected.
- Version 8.20.0 is affected.
- Version 8.19.0 is affected.
- Version 8.18.0 is affected.
- Version 8.17.0 is affected.
- Version 8.16.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.