VulnerabilityPublished 28 Oct 2026

CVE-2026-118265: labstack echo · Use of Less Trusted Source

Affects labstack echoSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 5.4.1 when convenient.

Data as of 28 Oct 2026, 19:27 UTC

CVSS 3.1 base score

5.3Medium

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

Patch: Available – fixed in 5.4.1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
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: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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

Upgrade labstack echo to 5.4.1.

Affected software

Product	Affected	Fixed in
labstackecho	Affected >=5.0.0 <5.4.1	Fixed in 5.4.1

AI-suggested

Upgrade Echo to version 5.4.1 or later, where the issue is fixed. Applications should avoid relying on the vulnerable ExtractIPFromRealIPHeader function in affected versions. No other mitigation is indicated by the vendor advisory.

Description

A vulnerability in the Echo Go web framework versions 5.0.0 through 5.4.0 allows client-supplied X-Real-IP headers to be trusted incorrectly. This can lead to spoofing of the client's IP address in applications relying on this value for security controls. The issue is fixed in version 5.4.1.

Impact

An attacker can spoof their IP address by supplying a crafted X-Real-IP header, potentially bypassing IP-based security controls like allowlists and rate limiting. This can lead to unauthorized access or evasion of restrictions. The vulnerability does not impact confidentiality or availability but affects the integrity of IP-based trust decisions.

Summary

Echo v5's ExtractIPFromRealIPHeader function validates the X-Real-IP header against a trusted range rather than the direct network peer. This allows an attacker to supply a spoofed IP address, such as a loopback or private address, which Echo then returns as the client's real IP. Applications using this extractor for IP allowlists, rate limiting, audit logs, or forwarding headers may trust attacker-controlled IP addresses. The vulnerability affects Echo versions from 5.0.0 up to but not including 5.4.1 and is resolved in 5.4.1. Echo v4 and the default direct extractor are not affected.

CWE-348Use of Less Trusted Source (opens in a new tab)
Base weakness
The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Cache Poisoning (opens in a new tab)
DNS Cache Poisoning (opens in a new tab)
User-Controlled Filename (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
AJAX Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Oct 2026, 19:27 UTC

WeaknessesCWE-348

Technical details

References

Community reviews

Related threats