SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2018-7159

The HTTP parser in all current versions of Node.js ignores spaces in the `Content-Length` header, allowing input such as `Content-Length: 1 2` to be interpreted as having a value of `12`.

MEDIUM 5.3EPSS 3.54%

Does this matter?

Lower severity and a low EPSS score (3.54%). Track it; it rarely justifies an emergency change on its own.

Description

The HTTP parser in all current versions of Node.js ignores spaces in the `Content-Length` header, allowing input such as `Content-Length: 1 2` to be interpreted as having a value of `12`. The HTTP specification does not allow for spaces in the `Content-Length` value and the Node.js HTTP parser has been brought into line on this particular difference. The security risk of this flaw to Node.js users is considered to be VERY LOW as it is difficult, and may be impossible, to craft an attack that makes use of this flaw in a way that could not already be achieved by supplying an incorrect value for `Content-Length`. Vulnerabilities may exist in user-code that make incorrect assumptions about the potential accuracy of this value compared to the actual length of the data supplied. Node.js users crafting lower-level HTTP utilities are advised to re-check the length of any input supplied after parsing is complete.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
3.54% probability · 89th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-115, CWE-20
Affected
nodejs/node.js
Source
cve-request@iojs.org
EPSS trend
0%3%5%27 October 2026: 3.54%27 October 202627 October 2026

EPSS 3.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.