TOTOLINK A950RG MAC Filter cstecgi.cgi setMacFilterRules stack-based overflow
Affects TOTOLINK A950RG firmware V4.1.2cu.5268_B20221104 when setMacFilterRules receives a non-zero addEffect value. No vendor rating or fix is listed.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected firmware is TOTOLINK A950RG V4.1.2cu.5268_B20221104. The vulnerable path is reached by posting to setting/setMacFilterRules with a non-zero addEffect value.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity9.4/10CVSS 9.4
- No patch5/5No patch listed yet
What would change the score
- Would score about 72 if added to CISA KEV
- Would score about 67 if CISA's SSVC rates exploitation active
- Would score about 29 if CISA's SSVC rates it automatable
CVE-2026-121600 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.4 (critical) and affects A950RG; no fixed version is listed yet.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.47% · 40th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 22/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The TOTOLINK A950RG router's MAC Filter feature, specifically its web management interface (cstecgi.cgi), is affected by this vulnerability. An attacker on the network could send a crafted request to overflow a memory buffer, which could crash the device or potentially allow arbitrary code to run on it.
Read the original description
A flaw has been found in TOTOLINK A950RG 4.1.2cu.5268_B20221104. Affected by this vulnerability is the function setMacFilterRules of the file /cgi-bin/cstecgi.cgi of the component MAC Filter Handler. This manipulation of the argument addEffect causes stack-based buffer overflow. The attack can be initiated remotely. The exploit has been published and may be used.
What to do
Check whether your setup matches what the bug needs.
Affected firmware is TOTOLINK A950RG V4.1.2cu.5268_B20221104. The vulnerable path is reached by posting to setting/setMacFilterRules with a non-zero addEffect value.Workaround: The checked facts list no fix and no workaround, so this page cannot name a mitigation.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- TOTOLINK A950RG
4.1.2cu.5268_B20221104
Evidence 6
- Advisory
- Advisory
- Advisory
- Advisory
- Exploit
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121600
Is CVE-2026-121600 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The MAC filter handler overflows a stack buffer, overwriting the saved return address. The advisory says that address can be aimed at a fixed location, which could allow control of program execution on the device.Source: gist.github.com
Which versions are affected by CVE-2026-121600?
A950RG: version 4.1.2cu.5268_B20221104.Source: cve.now feed data
Am I affected, and how do I check?
The advisory names TOTOLINK A950RG firmware V4.1.2cu.5268_B20221104. The vulnerable path is a POST to setting/setMacFilterRules with a non-zero addEffect value. To check, compare the firmware version shown on the device against that build and see whether that endpoint is used with a non-zero addEffect value.Source: gist.github.com
What if there's no patch?
The checked facts list no fix and no workaround, so this page cannot name a mitigation.Source: gist.github.com