How severe is CVE-2026-34441?

CVE-2026-34441 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-34441 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34441?

CVE-2026-34441 affects Yhirose Cpp-httplib. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34441?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34441 have an EU (EUVD) identifier?

Yes. CVE-2026-34441 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17672.

When was CVE-2026-34441 published?

CVE-2026-34441 was published on 2026-03-31 and last updated on 2026-06-17.

CVE-2026-34441

CVE-2026-34441 is a medium-severity vulnerability in Yhirose Cpp-httplib with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17672
Weakness: CWE-444
Affected product: Yhirose Cpp-httplib
Published: 2026-03-31
Last modified: 2026-06-17

Description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread body bytes remain on the TCP stream and are interpreted as the start of a new HTTP request. An attacker can embed an arbitrary HTTP request inside the body of a GET request, which the server processes as a separate request. This issue has been patched in version 0.40.0.

Frequently asked questions

What is CVE-2026-34441?: cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.40.0, cpp-httplib is vulnerable to HTTP Request Smuggling. The server's static file handler serves GET responses without consuming the request body. On HTTP/1.1 keep-alive connections, the unread body bytes remain on the TCP stream and are interpreted as the start of a new HTTP request. An attacker can embed an arbitrary HTTP request inside the body of a GET request, which the server processes as a separate request. This issue has been patched in version 0.40.0.
How severe is CVE-2026-34441?: CVE-2026-34441 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-34441 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34441?: CVE-2026-34441 affects Yhirose Cpp-httplib. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34441?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34441 have an EU (EUVD) identifier?: Yes. CVE-2026-34441 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17672.
When was CVE-2026-34441 published?: CVE-2026-34441 was published on 2026-03-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*

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