CVE-2025-34335: AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenti

Q: How do I fix CVE-2025-34335?

fax server: upgrade to newer than 2.6.23; interactive voice response: upgrade to 2.6.23. Exact commands for each OS are on this page.

Q: Is CVE-2025-34335 being exploited?

CVE-2025-34335 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-2025-34335 affect?

CVE-2025-34335 affects fax server, interactive voice response. Severity is high (CVSS 8.8). AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in the license activation workflow handled by AudioCodes_files/ActivateLicense.php. When a l

Q: How urgent is CVE-2025-34335?

Priority 57/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADEUPGRADE

CVE-2025-34335 is a high-severity flaw (CVSS 8.8) affecting fax server, interactive voice response. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in the license activation workflow handled by AudioCodes_files/ActivateLicense.php. When a license file is uploaded, the application derives a new filename by combining a generated base name with the attacker-controlled extension portion of the original upload name, then constructs a command line for

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	2.8% (top 13%)
CISA exploited list	No
Weakness	CWE-78
Published	2025-11-19
Last modified	2026-10-18

Publisher (CNA): VulnCheck · Vendor: audiocodes

Last updated 2026-10-18 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-11-19 17:15 UTCPublished CVE record published
2026-10-18 20:10 UTCUpdated Record last modified

audiocodes fax server UPGRADE

Affected: <= 2.6.23

Fixed in: newer than 2.6.23

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy fax-server || rpm -q fax-server || fax-server --version

2. UPGRADE to newer than 2.6.23 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fax-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fax-server

Note

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

audiocodes interactive voice response UPGRADE

Affected: < 2.6.23

Fixed in: 2.6.23

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy interactive-voice-response || rpm -q interactive-voice-response || interactive-voice-response --version

2. UPGRADE to 2.6.23 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade interactive-voice-response

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade interactive-voice-response

Note

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

Exact fixes by distribution

Fedora ELN · openjpeg · FIXED · 2.5.4-5.eln159 · FEDORA-2026-1a5f60f401 · source

sudo dnf upgrade --advisory=FEDORA-2026-1a5f60f401

Fedora 46 · trustedqsl · FIXED · 2.8.7-1.fc46 · FEDORA-2026-6b1bc90ebc · source

sudo dnf upgrade --advisory=FEDORA-2026-6b1bc90ebc

Public exploits and detection

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

Write-up: pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txt
Write-up: pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.html

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-2025-34335?

fax server: upgrade to newer than 2.6.23; interactive voice response: upgrade to 2.6.23. Exact commands for each OS are on this page.

Is CVE-2025-34335 being exploited?

CVE-2025-34335 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-2025-34335 affect?

CVE-2025-34335 affects fax server, interactive voice response. Severity is high (CVSS 8.8). AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in the license activation workflow handled by AudioCodes_files/ActivateLicense.php. When a l

How urgent is CVE-2025-34335?

Priority 57/100. High severity; Public exploit reference

Software pages

PHP vulnerabilities

Related CVEs

CVE-2025-34329 CRITICAL 9.8 UPGRADE UPGRADE AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an unauthen
CVE-2025-34328 CRITICAL 9.8 UPGRADE UPGRADE AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 include a web admi
CVE-2025-34334 HIGH 8.8 UPGRADE UPGRADE AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 are vulnerable to
CVE-2025-34331 HIGH 7.5 UPGRADE UPGRADE AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 contain an unauthe
CVE-2025-34330 MEDIUM 5.3 UPGRADE UPGRADE AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 include a web admi

References

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