- Exploited
- No known exploitation
- Fix
- Fixed in 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, and 2 more
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, or one of 2 more.
- Last modified
- 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? →
- 20/100 · provisional
- 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 Linux kernel's xen-netback driver, which handles network traffic for Xen guests, has a use-after-free bug in how it reports statistics through sysfs. An attacker who can trigger a connection error with the frontend, for example by feeding bad Xenstore data from a guest, could read memory that has already been freed or has been reused.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
In the Linux kernel, the following vulnerability has been resolved:
xen-netback: Fix UAF when reading statistics data
The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible.
Fix that by calling synchronize_net() before freeing the queue data.
This is XSA-526 / CVE-2026-100080
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach20/20Affects Linux kernel (software on nearly every server, desktop or phone)
- Severity?/10Unknown. No CVSS score or vendor rating
- No patch0/5No signal
What would change the score
- Would score about 75 if added to CISA KEV
- Would score about 70 if CISA's SSVC rates exploitation active
- Would score about 42 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, or one of 2 more.
Timeline
- CVE published
- First seen by cve.now
- Record last updated
Affected versions
- Linux Linux
fixed in 5.10.274; fixed in 5.15.225; fixed in 6.1.192; fixed in 6.6.162; fixed in 6.12.116; fixed in 6.18.62; fixed in 7.3.3
- Linux Linux
Version range not reported
Evidence 9
- Link
- Link
- Link
- Link
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-100080
Is CVE-2026-100080 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
Which versions are affected by CVE-2026-100080?
Linux: before 5.10.274; before 5.15.225; before 6.1.192; before 6.6.162; before 6.12.116; before 6.18.62; before 7.3.3.Source: cve.now feed data
How do I fix CVE-2026-100080?
Upgrade to a fixed version: 5.10.274, 5.15.225, 6.1.192, 6.6.162, 6.12.116, or one of 2 more.Source: cve.now feed data