CVE-2025-38261: Linux kernel · riscv: save the SR_SUM status over switches
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.14.0-1015.15~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.14.0-1015.15~24.04.1, 6.14.0-1014.14~24.04.1, 6.14.0-1007.7 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Jul 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
Upgrade to a fixed release listed under Affected software.
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 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions. The fix evaluates put_user() arguments before enabling user access and ensures SR_SUM is saved and restored during context switches. Users should update to patched kernel versions as per vendor advisories. No additional mitigations are indicated.
Description
A vulnerability in the Linux kernel's RISC-V architecture was fixed by ensuring the SR_SUM status is properly saved and restored during thread/task switches. The issue caused kernel crashes under heavy load due to improper handling of user memory access in schedule_tail. The root cause involved the put_user() macro evaluating arguments within a user-access enabled section, potentially clearing SR_SUM and causing kernel panics. The fix evaluates put_user() arguments before enabling user access and ensures switch_to() saves and restores SR_SUM correctly.
References
- ubuntu.com/security/CVE-2025-38261 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38261 (opens in a new tab)
- git.kernel.org/linus/788aa64c01f1262310b4c1fb827a36df170d86ea (opens in a new tab)
- git.kernel.org/stable/c/69ea599a8dab93a620c92c255be4239a06290a77 (opens in a new tab)
- git.kernel.org/stable/c/788aa64c01f1262310b4c1fb827a36df170d86ea (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7834-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7856-1 (opens in a new tab)