HOMEVULNERABILITIESCVE-2020-26887
HIGHPOC

CVE-2020-26887

NVD-CWE-noinfoPublished: October 23, 2020· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official Description

FRITZ!OS before 7.21 on FRITZ!Box devices allows a bypass of a DNS Rebinding protection mechanism.

NVD Source

Technical Analysis

CVE-2020-26887 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

A proof-of-concept (PoC) exploit exists for CVE-2020-26887. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

avm2 product(s)
fritz\!box 7490 firmwarefritz\!box 7490
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttp://packetstormsecurity.com/files/159606/FRITZ-Box-7.20-DNS-Rebinding-Protection-Bypass.html
ADVISORYhttps://en.avm.de/news/
ADVISORYhttps://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analyses
ADVISORYhttp://packetstormsecurity.com/files/159606/FRITZ-Box-7.20-DNS-Rebinding-Protection-Bypass.html
ADVISORYhttps://en.avm.de/news/
ADVISORYhttps://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analyses

All References (6)

→
http://packetstormsecurity.com/files/159606/FRITZ-Box-7.20-DNS-Rebinding-Protection-Bypass.htmlExploit · Third Party Advisory · VDB Entry
→
https://en.avm.de/news/Vendor Advisory
→
https://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analysesThird Party Advisory
→
http://packetstormsecurity.com/files/159606/FRITZ-Box-7.20-DNS-Rebinding-Protection-Bypass.htmlExploit · Third Party Advisory · VDB Entry
→
https://en.avm.de/news/Vendor Advisory
→
https://www.redteam-pentesting.de/en/advisories/-advisories-publicised-vulnerability-analysesThird Party Advisory

Quick Facts

CVE IDCVE-2020-26887
CVSS Score7.8 / 10
SeverityHIGH
WeaknessNVD-CWE-noinfo
CISA KEVNo
ExploitPOC
Affected1 vendor(s)
PublishedOct 23, 2020

Related CVEs (NVD-CWE-noinfo)

CVE-2010-3556
10.0
CVE-2010-3558
10.0
CVE-2010-3554
10.0
CVE-2012-1398
10.0
CVE-2010-3553
10.0
CVE-2010-3559
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-26887 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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