CVE-2015-5739
CVE-2015-5739 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: 10% (95th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-444
- Affected product: Golang Go
- Published:
- Last modified:
Description
The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length."
Frequently asked questions
- What is CVE-2015-5739?
- The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length."
- How severe is CVE-2015-5739?
- CVE-2015-5739 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-2015-5739 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2015-5739?
- CVE-2015-5739 primarily affects Golang Go. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2015-5739?
- 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-2015-5739 published?
- CVE-2015-5739 was published on 2017-10-18 and last updated on 2026-06-17.
References
- http://lists.fedoraproject.org/pipermail/package-announce/2015-October/167997.html
- http://lists.fedoraproject.org/pipermail/package-announce/2015-October/168029.html
- http://rhn.redhat.com/errata/RHSA-2016-1538.html
- http://seclists.org/oss-sec/2015/q3/237
- http://seclists.org/oss-sec/2015/q3/292
- http://seclists.org/oss-sec/2015/q3/294
- http://www.securityfocus.com/bid/76281
- https://bugzilla.redhat.com/show_bug.cgi?id=1250352
- https://github.com/golang/go/commit/117ddcb83d7f42d6aa72241240af99ded81118e9
Affected products (16)
- cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:21:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.2:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.2:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
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