Critical

CVE-2018-1000007 — libcurl Credential Leak via Custom Headers on Redirects

libcurl 7.1 through 7.57.0 might accidentally leak authentication data to third parties. When asked to send custom headers in its HTTP requests, libcurl will send that set of headers first to the host in the initial URL but also, if asked to follow redirects and a 30X HTTP response code is returned, to the host mentioned in URL in the `Location:` response header value. Sending the same set of headers to subsequent hosts is in particular a problem for applications that pass on custom `Authorization:` headers, as this header often contains privacy sensitive information or data that could allow others to impersonate the libcurl-using client's request.

Published Jan 24, 2018 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: mitre

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 6.6% (30-day exploitation probability)+14
Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

6.58%

ahead of 94% of scored CVEs · Oct 15, 2026

Affects

Canonical

Ubuntu Linux and 13 more

CVSS base

9.8

Critical · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — curl.haxx.se (NIST National Vulnerability Database)
Documented patch — www.oracle.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Canonical Ubuntu Linux, Debian Debian Linux, Fujitsu M10-1 Firmware…).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
EPSS ahead of 94% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Canonical	Ubuntu Linux	version 12.04version 14.04version 16.04version 17.10	Vulnerable	NIST National Vulnerability Database
Debian	Debian Linux	version 8.0version 9.0version 7.0	Vulnerable	NIST National Vulnerability Database
Fujitsu	M10-1 Firmware	< xcp3070< xcp2361	Vulnerable	NIST National Vulnerability Database
Fujitsu	M10-4 Firmware	< xcp3070< xcp2361	Vulnerable	NIST National Vulnerability Database
Fujitsu	M10-4s Firmware	< xcp2361< xcp3070	Vulnerable	NIST National Vulnerability Database
Fujitsu	M12-1 Firmware	< xcp2361< xcp3070	Vulnerable	NIST National Vulnerability Database
Fujitsu	M12-2 Firmware	< xcp2361< xcp3070	Vulnerable	NIST National Vulnerability Database
Fujitsu	M12-2s Firmware	< xcp2361< xcp3070	Vulnerable	NIST National Vulnerability Database
Haxx	Curl	≥ 7.1 and ≤ 7.57.0	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux Desktop	version 7.0	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux Server	version 7.0	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux Server Aus	version 7.4	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux Server Eus	version 7.5version 7.4	Vulnerable	NIST National Vulnerability Database
Red Hat	Enterprise Linux Workstation	version 7.0	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	nvd@nist.gov via NIST National Vulnerability Database
9.8	CVSS 3.0	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
5.0	CVSS 2.0	Medium	10.0	2.9	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 6.58%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Analysis and videos

CVE-2018-1000007: libcurl Credential Leak via Custom Headers on Redirects
libcurl versions 7.1 through 7.57.0 can send custom headers, including Authorization headers, to hosts other than the original one when following HTTP 30X redirects. This can expose authentication data to third parties. NVD scores it CVSS 3.1 9.8 (critical), and the record does not list it in CISA KEV.

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · haxx/curl, debian/debian linux, canonical/ubuntu linux, redhat/enterprise linux desktop, redhat/enterprise linux server,
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Modified
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · Edição manual da equipe
2018
CVE published
Jan 24, 2018 · mitre

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

16 on the record

www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
Patch, Third Party Advisory, x_refsource_MISC, NIST National Vulnerability Database
curl.haxx.se/docs/adv_2018-b3bf.html
Patch, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2020:0544
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
usn.ubuntu.com/3554-2/
Third Party Advisory, vendor-advisory, x_refsource_UBUNTU, NIST National Vulnerability Database
www.openwall.com/lists/oss-security/2022/04/27/4
Mailing List, Third Party Advisory, mailing-list, x_refsource_MLIST, NIST National Vulnerability Database
access.redhat.com/errata/RHBA-2019:0327
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
usn.ubuntu.com/3554-1/
Third Party Advisory, vendor-advisory, x_refsource_UBUNTU, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2018:3558
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2018-1000007
GitHub Security Advisories
access.redhat.com/errata/RHSA-2018:3157
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2019:1543
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2020:0594
Third Party Advisory, vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database
www.debian.org/security/2018/dsa-4098
Third Party Advisory, vendor-advisory, x_refsource_DEBIAN, NIST National Vulnerability Database
www.securitytracker.com/id/1040274
Third Party Advisory, VDB Entry, vdb-entry, x_refsource_SECTRACK, NIST National Vulnerability Database
lists.debian.org/debian-lts-announce/2018/01/msg00038.html
Mailing List, Third Party Advisory, mailing-list, x_refsource_MLIST, NIST National Vulnerability Database
github.com/advisories/GHSA-g7x2-hrfp-pv5f
GitHub Security Advisories

Elsewhere on this site

Canonical
every CVE for this vendor

Related CVEs (same products)

High CVE-2026-82209 domain-scoped PSL domain cookie Sep 6, 2026
High CVE-2026-80229 OpenSSL provider use-after-free Sep 6, 2026
High CVE-2026-80230 OpenSSL pinning bypass Sep 6, 2026
High CVE-2026-80231 native CA store conn reuse Sep 6, 2026
High CVE-2026-80255 secure cookie attribute bypass with tab Sep 6, 2026
High CVE-2026-82208 wolfSSL CA-cache hit overrides callback Sep 6, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2018-1000007 is "libcurl Credential Leak via Custom Headers on Redirects", rated Critical. It affects Ubuntu Linux (Canonical); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 6.58% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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