VulnerabilityPublished 22 Aug 2026Updated 21 Oct 2026

CVE-2026-74728: Linux kernel · xfs: handle NULL b_addr in xfs_buf_free

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in d852729c5f4f830fbe7413df032e29459b3daf83 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in d852729c5f4f830fbe7413df032e29459b3daf83, ccf6738adcafa5ddbddc4e71b45d8a51b86643c7, 444ff50ece93060131ad84fbd3f378723d8ac243 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Aug 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to d852729c5f4f830fbe7413df032e29459b3daf83, ccf6738adcafa5ddbddc4e71b45d8a51b86643c7, 444ff50ece93060131ad84fbd3f378723d8ac243 or 3aa0c1d23ee1b9d9b340fb2f4736536e1408d706.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 5076a6040ca1613e616d84aecfaac5f932db84e0, < d852729c5f4f830fbe7413df032e29459b3daf83	Fixed in d852729c5f4f830fbe7413df032e29459b3daf83
LinuxLinux	Affected ≥ 5076a6040ca1613e616d84aecfaac5f932db84e0, < ccf6738adcafa5ddbddc4e71b45d8a51b86643c7	Fixed in ccf6738adcafa5ddbddc4e71b45d8a51b86643c7
LinuxLinux	Affected ≥ 5076a6040ca1613e616d84aecfaac5f932db84e0, < 444ff50ece93060131ad84fbd3f378723d8ac243	Fixed in 444ff50ece93060131ad84fbd3f378723d8ac243
LinuxLinux	Affected ≥ 5076a6040ca1613e616d84aecfaac5f932db84e0, < 3aa0c1d23ee1b9d9b340fb2f4736536e1408d706	Fixed in 3aa0c1d23ee1b9d9b340fb2f4736536e1408d706
LinuxLinux	Affected =6.9	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: xfs: handle NULL b_addr in xfs_buf_free When xfs_buf_alloc_backing_mem() fails, xfs_buf_free() is called with bp->b_addr still NULL. The code falls through to the folio_put path which calls virt_to_folio(NULL), dereferencing an invalid address and causing a kernel crash. Call Trace: xfs_buf_free+0x25f/0x510 xfs_buf_alloc+0xc98/0x19b0 xfs_buf_find_insert+0x55/0x14d0 xfs_buf_get_map+0x122b/0x17c0 xfbtree_init_leaf_block+0x11c/0x4a0 xfbtree_init+0x1bb/0x460 xrep_rmap_setup_scan+0x100/0x1f0 xrep_rmapbt+0x41/0xc0 Fix this by skipping folio_put() when bp->b_addr is NULL.

References

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