CVE-2025-37939: Linux kernel · libbpf: Fix accessing BTF.ext core_relo header
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 20 May 2025
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.
What to do
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-realtimepkg:deb/ubuntu/linux-realtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Nvidia-BlueField 24.04 LTSlinux-bluefieldpkg:deb/ubuntu/linux-bluefield?arch=source&distro=bluefield/nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: libbpf: Fix accessing BTF.ext core_relo header Update btf_ext_parse_info() to ensure the core_relo header is present before reading its fields. This avoids a potential buffer read overflow reported by the OSS Fuzz project.
References
- ubuntu.com/security/CVE-2025-37939 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37939 (opens in a new tab)
- git.kernel.org/linus/0a7c2a84359612e54328aa52030eb202093da6e2 (opens in a new tab)
- git.kernel.org/stable/c/0a7c2a84359612e54328aa52030eb202093da6e2 (opens in a new tab)
- git.kernel.org/stable/c/3a67f60f0a8be10cea7a884a1a00e9feb6645657 (opens in a new tab)
- git.kernel.org/stable/c/d529411ec44535308c5d59cbeff74be6fe14b479 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)