CVE-2025-54123: Hoverfly is an open source API simulation tool

Q: How do I fix CVE-2025-54123?

hoverfly: upgrade to 1.12.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-54123 being exploited?

CVE-2025-54123 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-54123 affect?

CVE-2025-54123 affects hoverfly. Severity is critical (CVSS 9.8). Hoverfly is an open source API simulation tool. In versions 1.11.3 and prior, the middleware functionality in Hoverfly is vulnerable to command injection vulnerability at `/api/v2/hoverfly/middleware` endpoint due to insufficient validation

Q: How urgent is CVE-2025-54123?

Priority 71/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2025-54123 is a critical-severity flaw (CVSS 9.8) affecting hoverfly. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Hoverfly is an open source API simulation tool. In versions 1.11.3 and prior, the middleware functionality in Hoverfly is vulnerable to command injection vulnerability at `/api/v2/hoverfly/middleware` endpoint due to insufficient validation and sanitization in user input. The vulnerability exists in the middleware management API endpoint `/api/v2/hoverfly/middleware`. This issue is born due to combination of three code level flaws: Insufficient I

Why this priority

Critical severity
EPSS top 4%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	10.9% (top 4%)
CISA exploited list	No
Weakness	CWE-20, CWE-78
Published	2025-09-10
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: hoverfly

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-09-10 19:15 UTCPublished CVE record published
2026-06-17 09:39 UTCUpdated Record last modified

hoverfly hoverfly UPGRADE

Affected: < 1.12.0

Fixed in: 1.12.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy hoverfly || rpm -q hoverfly || hoverfly --version

2. UPGRADE to 1.12.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade hoverfly

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade hoverfly

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Go · github.com/SpectoLabs/hoverfly · NO FIX YET · vulnerable: <= 1.11.3 · source

Fedora ELN · gram_grep · FIXED · 0.10.4-1.eln159 · FEDORA-2026-0808475f2a · source

sudo dnf upgrade --advisory=FEDORA-2026-0808475f2a

Fedora 46 · wesnoth · FIXED · 1.19.29-1.fc46 · FEDORA-2026-58f458e24e · source

sudo dnf upgrade --advisory=FEDORA-2026-58f458e24e

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: kasem545/CVE-2025-54123-Poc (7 stars)
GitHub PoC: 0xk4rth1/CVE-2025-54123 (2 stars)
GitHub PoC: 0x00phantom-hat/Hoverfly-1.11.3-RCE-CVE-2025-54123-Exploit (1 stars)
Write-up: github.com/SpectoLabs/hoverfly/security/advisories/GHSA-r4h8-hfp2-ggmf
Nuclei scan template: Hoverfly <= 1.11.3 - Remote Code Execution

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-54123?

hoverfly: upgrade to 1.12.0. Exact commands for each OS are on this page.

Is CVE-2025-54123 being exploited?

CVE-2025-54123 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-54123 affect?

CVE-2025-54123 affects hoverfly. Severity is critical (CVSS 9.8). Hoverfly is an open source API simulation tool. In versions 1.11.3 and prior, the middleware functionality in Hoverfly is vulnerable to command injection vulnerability at `/api/v2/hoverfly/middleware` endpoint due to insufficient validation

How urgent is CVE-2025-54123?

Priority 71/100. Critical severity; EPSS top 4%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-54376 HIGH 7.5 UPGRADE Hoverfly is an open source API simulation tool
CVE-2024-45388 HIGH 7.5 UPGRADE Hoverfly is a lightweight service virtualization/ API simulation / API mocking tool for developers and testers

References

← Back to latest CVEs