CVE-2026-42154
Memory Exhaustion in Prometheus via Snappy Compression
Publication date: 2026-05-04
Last updated on: 2026-05-04
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| prometheus | prometheus | to 3.11.3 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-789 | The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. |
| CWE-400 | The product does not properly control the allocation and maintenance of a limited resource. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in Prometheus versions prior to 3.5.3 and 3.11.3, specifically in the remote read endpoint (/api/v1/read). The issue is that the system does not validate the declared decoded length in a snappy-compressed request body before allocating memory. This means an attacker can send a small payload that tricks the system into allocating a very large amount of memory.
Because the memory allocation is based on unvalidated input, an unauthenticated attacker can cause excessive memory usage, potentially leading to the exhaustion of available memory and crashing the Prometheus process.
How can this vulnerability impact me? :
The primary impact of this vulnerability is a denial of service (DoS) condition. An attacker can cause Prometheus to consume excessive memory by sending specially crafted requests, which can lead to the Prometheus process crashing.
This can disrupt monitoring and alerting services that rely on Prometheus, potentially causing loss of visibility into system health and delays in detecting other issues.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade Prometheus to version 3.5.3 or 3.11.3 or later, as these versions contain the patch that fixes the issue.