Request smuggling via Content-Length integer truncation
Published Oct 16, 2026 · Updated Oct 16, 2026
Integer truncation in PUPnP libupnp before 2.0.2 allows remote attackers to smuggle requests via HTTP Content-Length headers. In httpparser.c, raw_to_int narrows strtol's long result to int without an upper-bound check, changing the accepted body length. Unauthenticated adjacent-network access to an LP64 deployment is required; persistent or proxied contexts permit request smuggling, while oversized lengths leave workers waiting for body data and interrupt service.
Summary
What happened
Integer truncation in PUPnP libupnp before 2.0.2 allows remote attackers to smuggle requests via HTTP Content-Length headers. In httpparser.c, raw_to_int narrows strtol's long result to int without an upper-bound check, changing the accepted body length. Unauthenticated adjacent-network access to an LP64 deployment is required; persistent or proxied contexts permit request smuggling, while oversized lengths leave workers waiting for body data and interrupt service.
The record
- CVE
- CVE-2026-57488
- Published
- Oct 16, 2026
- Updated
- Oct 16, 2026
- Vendor
- PUPnP
- Product
- libupnp
- Classifications
- CWE-190, CWE-444, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 16, 2026CVE publishedPublication date reported by the CVE source.
- Oct 16, 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.
- Affected versionversion=< 2.0.2
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.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Upstream Content-Length truncation proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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