CVE-2023-41338· NVD / CVE Program· CNA GitHub_M

Vulnerability in Ctx.IsFromLocal() in gofiber

Noroxi assessment

Priority: Monitor (action score 21/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.65% (FIRST EPSS); higher than 50.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: github.com/gofiber/fiber/v2 (Go) 2.49.2, 2.49.2-0.20230906112033-b8c9ede6efa2.

Low priority for now. Upgrade to github.com/gofiber/fiber/v2 (Go) 2.49.2, 2.49.2-0.20230906112033-b8c9ede6efa2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Fiber is an Express inspired web framework built in the go language. Versions of gofiber prior to 2.49.2 did not properly restrict access to localhost. This issue impacts users of our project who rely on the `ctx.IsFromLocal` method to restrict access to localhost requests. If exploited, it could allow unauthorized access to resources intended only for localhost. Setting `X-Forwarded-For: 127.0.0.1` in a request from a foreign host, will result in true for `ctx.IsFromLocal`. Access is limited to the scope of the affected process. This issue has been patched in version `2.49.2` with commit `b8c9ede6`. Users are advised to upgrade. There are no known workarounds to remediate this vulnerability without upgrading to the patched version.

MediumCVSS 5.3 · v3.1—No exploit Fix available

Pre-auth

Published: Sep 8, 2023
Updated: Jun 17, 2026
EPSS: 0.6% · 50th percentile
CWE: CWE-670

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.3
CNA · GitHub_M: 5.3; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
gofiber	fiber	cpe:2.3:a:gofiber:fiber

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

gofiber fiberbefore 2.49.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

gofiber fiber
- < 2.49.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Go	github.com/gofiber/fiber	up to and including 1.14.6	—
Go	github.com/gofiber/fiber/v2	before 2.49.2	2.49.2
Go	github.com/gofiber/fiber/v2	before 2.49.2-0.20230906112033-b8c9ede6efa2	2.49.2-0.20230906112033-b8c9ede6efa2

Same product

gofiber: all records

Other highest-scoring records for the same primary product.

CVE-2024-38513Fiber Session Middleware Token Injection Vulnerability
39Monitor
CVE-2024-25124Fiber has Insecure CORS Configuration, Allowing Wildcard Origin with Credentials
39Monitor
CVE-2025-66630Fiber insecurely fallsback in utils.UUIDv4() / utils.UUID() — predictable / zero‑UUID on crypto/rand failure
36Monitor
CVE-2023-45141CSRF Token Validation Vulnerability in fiber
35Monitor
CVE-2023-45128CSRF Token Reuse Vulnerability in fiber
35Monitor
CVE-2025-54801Fiber Susceptible to Crash via `BodyParser` Due to Unvalidated Large Slice Index in Decoder
34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Go:github.com/gofiber/fiber/v2	2.49.2	Package registry (OSV)
Go:github.com/gofiber/fiber/v2	2.49.2-0.20230906112033-b8c9ede6efa2	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

gofiber/fibercommit b8c9ede

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: low · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: Low
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-670 · Always-Incorrect Control Flow Implementation

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:47 PM UTC

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References

developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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