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🛡️ CVE-2026-21640 — revive-adserver

🟢 CVSS 2.7 — Low ✅ No Known Exploit CWE-134 NVD
2.7
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

HackerOne community member Faraz Ahmed (PakCyberbot) has reported a format string injection in the Revive Adserver settings. When specific character combinations are used in a setting, the admin user console could be disabled due to a fatal PHP error.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs administrative privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: High — administrative rights are needed first.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: Low — limited, and the attacker does not choose what is affected.
  • Availability impact: None.

Weakness class

CVE-2026-21640 is classified as CWE-134: Externally Controlled Format String. User input is used as a format string, letting an attacker read or write memory through format specifiers.

Affected software

CVE-2026-21640 is recorded against 1 package.

  • revive-adserver (from 6.0.0 up to 6.0.4)

Timeline and source

Published on 20 January 2026 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

hackerone.com

Other advisories for this package

revive-adserver has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-134: Externally Controlled Format String) in other software:

Details

Severity LOW
CVSS Score 2.7
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
CWE CWE-134
Public Exploit ✅ No
Source NVD
Published 2026-01-20
Updated 2026-08-20
Modified 2026-06-17
Fix URL N/A

Affected Packages

Software From version Fixed in
revive-adserver 6.0.0 6.0.4

References

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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