How severe is CVE-2015-5741?

CVE-2015-5741 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2015-5741 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-5741?

CVE-2015-5741 primarily affects Golang Go. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-5741?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2015-5741 published?

CVE-2015-5741 was published on 2020-02-08 and last updated on 2026-06-17.

CVE-2015-5741

CVE-2015-5741 is a critical-severity vulnerability in Golang Go with a CVSS 3.x base score of 9.8. 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: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-444
Affected product: Golang Go
Published: 2020-02-08
Last modified: 2026-06-17

Description

The net/http library in net/http/transfer.go in Go before 1.4.3 does not properly parse HTTP headers, which allows remote attackers to conduct HTTP request smuggling attacks via a request that contains Content-Length and Transfer-Encoding header fields.

Frequently asked questions

What is CVE-2015-5741?: The net/http library in net/http/transfer.go in Go before 1.4.3 does not properly parse HTTP headers, which allows remote attackers to conduct HTTP request smuggling attacks via a request that contains Content-Length and Transfer-Encoding header fields.
How severe is CVE-2015-5741?: CVE-2015-5741 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2015-5741 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-5741?: CVE-2015-5741 primarily affects Golang Go. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-5741?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2015-5741 published?: CVE-2015-5741 was published on 2020-02-08 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack:7.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack:8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*

More vulnerabilities in Golang Go

CVE-2025-68121 — Critical (CVSS 10.0): During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between…
CVE-2026-27143 — Critical (CVSS 9.8): Arithmetic over induction variables in loops were not correctly checked for underflow or overflow. As a result, the…
CVE-2024-24790 — Critical (CVSS 9.8): The various Is methods (IsPrivate, IsLoopback, etc) did not work as expected for IPv4-mapped IPv6 addresses, returning…
CVE-2023-39320 — Critical (CVSS 9.8): The go.mod toolchain directive, introduced in Go 1.21, can be leveraged to execute scripts and binaries relative to the…
CVE-2023-29405 — Critical (CVSS 9.8): The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a…
CVE-2023-29404 — Critical (CVSS 9.8): The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a…

All CVEs affecting Golang Go →

Other CWE-444 (HTTP Request/Response Smuggling) vulnerabilities

CVE-2025-1867 — Critical (CVSS 10.0): Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in ithewei libhv allows…
CVE-2022-22536 — Critical (CVSS 10.0): SAP NetWeaver Application Server ABAP, SAP NetWeaver Application Server Java, ABAP Platform, SAP Content Server 7.53…
CVE-2018-3907 — Critical (CVSS 10.0): An exploitable vulnerability exists in the REST parser of video-core's HTTP server of the Samsung SmartThings Hub…
CVE-2025-55315 — Critical (CVSS 9.9): Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized…
CVE-2020-15049 — Critical (CVSS 9.9): An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request…
CVE-2026-13763 — Critical (CVSS 9.8): Inconsistent interpretation of HTTP/2 requests in AWS Application Load Balancer with AWS WAF enabled might allow remote…

Browse all CWE-444 (HTTP Request/Response Smuggling) vulnerabilities →