CVE-2015-5739
The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP...
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."
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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."
- Record
CVE-2015-5739- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-444
- Updated
- 2026-11-02
CVE List No score
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."
- Record
CVE-2015-5739- Updated
- 2026-11-02
EUVDEUVD-2015-5685 No score
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."
- Record
EUVD-2015-5685- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-92gr-8fh9-j8vq
The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP...
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."
- Record
GHSA-92gr-8fh9-j8vq- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-444
- Updated
- 2026-11-02
OSVRHSA-2016:1538
Red Hat Security Advisory: golang security, bug fix, and enhancement update
- Record
RHSA-2016:1538- CVSS 3.0
- 5.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
OSVUBUNTU-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."
- Record
UBUNTU-CVE-2015-5739- CVSS 3.0
- 9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGO-2021-0159 No score
Request smuggling due to improper header parsing in net/http
HTTP headers were not properly parsed, which allows remote attackers to conduct HTTP request smuggling attacks via a request that contains Content-Length and Transfer-Encoding header fields.
- Record
GO-2021-0159- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
stdlibGo |
before 1.4.3 | 1.4.3 |
golangRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
golang-binRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
golang-docsRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
golang-miscRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
golang-srcRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
golang-testsRed Hat:enterprise_linux:7::server |
before 0:1.6.3-1.el7_2.1 | 0:1.6.3-1.el7_2.1 |
gccgo-4.9Ubuntu:14.04:LTS |
All versions, plus listed versions 4.9-20140213-0ubuntu14.9-20140213-0ubuntu24.9-20140217-0ubuntu14.9-20140222-0ubuntu14.9-20140303-0ubuntu2 Show 6 moreShow less4.9-20140303-0ubuntu34.9-20140321-0ubuntu14.9-20140330-0ubuntu14.9-20140406-0ubuntu14.9.1-0ubuntu14.9.3-0ubuntu4 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2015-5739 is a critical vulnerability (CVSS 9.8) in Golang Go, published October 18, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 9.62%, the 95th percentile. Fixed in stdlib 1.4.3.
References
seclists.org/oss-sec/2015/q3/292
lists.fedoraproject.org/pipermail/package-announce/2015-October/167997.html
rhn.redhat.com/errata/RHSA-2016-1538.html
bugzilla.redhat.com/show_bug.cgi?id=1250352
Show 37 moreShow less
securityfocus.com/bid/76281
github.com/golang/go/commit/117ddcb83d7f42d6aa72241240af99ded81118e9
nvd.nist.gov/vuln/detail/CVE-2015-5739
go.dev/cl/13148
go.googlesource.com/go/+/26049f6f9171d1190f3bbe05ec304845cfe6399f
groups.google.com/g/golang-announce/c/iSIyW4lM4hY/m/ADuQR4DiDwAJ
access.redhat.com/errata/RHSA-2016:1538
security.access.redhat.com/data/csaf/v2/advisories/2016/rhsa-2016_1538.json
cve.org/CVERecord?id=CVE-2015-5739
ubuntu.com/security/CVE-2015-5739