CVE-2025-40241: Linux kernel · erofs: fix crafted invalid cases for encoded extents
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.17.0-1011.11 : patch Linux kernel soon.
Data as of 26 Oct 2026, 11:42 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.17.0-1011.11, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 +1
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 4 Dec 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 Linux kernel to 6.17.0-1011.11, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 or 6.17.0-1007.7~24.04.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| linux-hwe-edge | Affected
| Fixed in
|
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel to address the crafted invalid cases for encoded extents in EROFS. Users should apply the official Linux kernel updates that include this patch. Since no specific patch links or vendor advisories are provided here, users should monitor the official Linux kernel repositories and distributions for the relevant security updates.
Description
In the Linux kernel, the following vulnerability has been resolved: erofs: fix crafted invalid cases for encoded extents Robert recently reported two corrupted images that can cause system crashes, which are related to the new encoded extents introduced in Linux 6.15: - The first one [1] has plen != 0 (e.g. plen == 0x2000000) but (plen & Z_EROFS_EXTENT_PLEN_MASK) == 0. It is used to represent special extents such as sparse extents (!EROFS_MAP_MAPPED), but previously only plen == 0 was handled; - The second one [2] has pa 0xffffffffffdcffed and plen 0xb4000, then "cur [0xfffffffffffff000] += bvec.bv_len [0x1000]" in "} while ((cur += bvec.bv_len) < end);" wraps around, causing an out-of-bound access of pcl->compressed_bvecs[] in z_erofs_submit_queue(). EROFS only supports 48-bit physical block addresses (up to 1EiB for 4k blocks), so add a sanity check to enforce this.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40241 (opens in a new tab)
- git.kernel.org/stable/c/00d8fe0b72f4ca0a983abced36aad2160038c421 (opens in a new tab)
- git.kernel.org/stable/c/a429b76114aaca3ef1aff4cd469dcf025431bd11 (opens in a new tab)
- ubuntu.com/security/CVE-2025-40241 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40241 (opens in a new tab)
- git.kernel.org/linus/a429b76114aaca3ef1aff4cd469dcf025431bd11 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)