CVE-2026-63836: Linux kernel · batman-adv: tp_meter: avoid divide-by-zero for dec_cwnd
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 12 Nov 2026, 20:41 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
AI-suggested
A fix has been implemented in the Linux kernel to correct the calculation and avoid the divide-by-zero condition. Users should apply the official kernel updates that include this fix once available.
Description
A vulnerability in the Linux kernel's batman-adv module's tp_meter component involves a divide-by-zero error in the dec_cwnd calculation. The issue arises due to an arithmetic overflow when cwnd reaches a specific large value, causing a division by zero. The calculation has been corrected to avoid this overflow and prevent the invalid division.
References
- git.kernel.org/stable/c/35264c4d46067d6312871488c810cef387f8c1f6 (opens in a new tab)
- git.kernel.org/stable/c/1381b021bf886b793fa5ffb895a8efae7ba0318f (opens in a new tab)
- git.kernel.org/stable/c/d08b69da40a101df1e28bfe1e8fa7a09ffa41107 (opens in a new tab)
- git.kernel.org/stable/c/cd74176cf1685f35a2e5f212d15748bbfecb53b6 (opens in a new tab)
- git.kernel.org/stable/c/ac229c86e49fdb96d91f51bc2fa37a9c4f58c44f (opens in a new tab)
- git.kernel.org/stable/c/7d2a44bc6bbe39aed03c68864aa0e54e04a50278 (opens in a new tab)
- git.kernel.org/stable/c/585616dab0aa9c45bc11b2c8082ca78533bc00e9 (opens in a new tab)
- git.kernel.org/stable/c/33ccd52f3cc9ed46ce395199f89aa3234dc83314 (opens in a new tab)