VulnerabilityPublished 13 May 2026Updated 15 Sep 2026

CVE-2026-7168: curl · Authentication Bypass by Capture-replay

Affects curlSource GCVE Database

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Not known to be exploited · CVSS 5.3 Medium.

Data as of 11 Nov 2026, 23:08 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CISA-ADP	CVSS 3.1	5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
curl curl	Affected =7.12.0 =8.15.0 =8.17.0	Fixed in–

AI-suggested

Until a fix is available, avoid reusing the same curl handle to connect to different HTTP proxies with Digest authentication to prevent leaking Proxy-Authorization headers.

Description

CVE-2026-7168 is a medium severity vulnerability in libcurl where reusing a curl handle to connect to a second HTTP proxy with Digest authentication causes the Proxy-Authorization header from the first proxy to be incorrectly sent to the second proxy. This can lead to an authentication bypass by replaying credentials intended for the first proxy to the second.

Impact

An attacker able to control or influence the proxy host parameter can cause libcurl to send authentication credentials intended for one proxy to another proxy. This may allow unauthorized access to the second proxy by replaying the Proxy-Authorization header, resulting in a confidentiality breach. There is no impact on integrity or availability.

Summary

This vulnerability occurs when libcurl is used to perform a transfer over an HTTP proxy (proxyA) with Digest authentication, and then the same handle is reused to connect to a different proxy (proxyB). libcurl mistakenly forwards the Proxy-Authorization header meant for proxyA to proxyB, potentially allowing unauthorized access to proxyB by replaying the captured authentication header. The issue affects specific versions of curl, including 7.12.0, 8.15.0, and 8.17.0. The CVSS 3.1 base score is 5.3 (medium), reflecting a network attack vector with low complexity and no privileges required, causing limited confidentiality impact without integrity or availability impact.

CWE-294Authentication Bypass by Capture-replay (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
Architecture and Design
Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.
Architecture and Design
Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Kerberoasting (opens in a new tab)
Remote Services with Stolen Credentials (opens in a new tab)
Windows Admin Shares with Stolen Credentials (opens in a new tab)
Reusing Session IDs (aka Session Replay) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2026, 23:08 UTC

WeaknessesCWE-294

Technical details

References

Community reviews

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