CVE-2026-80901: Linux kernel · ipvs: fix the checksum validations
Source GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 4 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: ipvs: fix the checksum validations ip_vs_in_icmp_v6() is missing checksum validation for ICMPv6 packets from clients. In fact, as for TCP/UDP we should validate the checksum for ICMP packets only when we mangle the packets on MASQ or on reply for tunnel. Also, Sashiko points out that handle_response_icmp() being common for IPv4 and IPv6 is missing the pseudo-header calculation while validating ICMPv6 messages from real servers which is a problem if checksum is not validated by the hardware. Fix the problems by creating ip_vs_checksum_common_check() helper and use it for TCP/UDP/ICMP both for IPv4 and IPv6. Rely on the nf_checksum() for validating the ICMP messages but use it also for TCP and UDP. Use correct IP offset for IP_VS_DBG_RL_PKT for TCP/UDP/SCTP. IPVS packets (TCP/UDP/SCTP/ICMP) do not need checksum validation on LOCAL_OUT (local clients or local real servers) and on FORWARD (traffic from servers on LAN). Do it only on LOCAL_IN, in case nf_checksum() is not called on PRE_ROUTING. Also, ip_vs_checksum_complete() can be marked static.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80901 (opens in a new tab)
- git.kernel.org/stable/c/00eb23829fd08df1b5e057cb6b625996a70e7e65 (opens in a new tab)
- git.kernel.org/stable/c/5558a85add073215b298f3e044ff9a6d86d714ae (opens in a new tab)
- git.kernel.org/stable/c/9cbe2c0fdb71904ee929b1851cdc1c73341a03c0 (opens in a new tab)
- git.kernel.org/stable/c/b3869d9b54e76dff64118dee4c8fd9302fcd5171 (opens in a new tab)
- git.kernel.org/stable/c/d418d73acf8be62744dc47359dfdde8c2148845d (opens in a new tab)
- git.kernel.org/stable/c/e876b75b9020a97bbdc79721e7fc749024891c65 (opens in a new tab)