In the Linux kernel, the following vulnerability has been resolved:
keys: Check the authorization payload in process keyring searches
An authorization payload and its saved credentials must remain valid
while search_process_keyrings_rcu() searches the requestor's keyrings.
The function validates the authorization key, then separately loads
payload.data[0] and unconditionally reads rka->cred. Validation does
not prevent request_key_auth_revoke() from clearing the payload.
A request-key helper can assume authority and fork a descendant that
inherits the authorization key. If the descendant misses in its own
keyrings, it falls back to the saved requestor credentials. Successful
target instantiation invalidates the authorization key without clearing
the payload. After the helper exits, UMH_WAIT_PROC returns to the
requester, which calls complete_request_key() and revokes that key.
With the descendant paused after validation, the paths can interleave
as follows:
- The descendant enters search_process_keyrings_rcu() under RCU and
key_validate() succeeds.
- The helper instantiates the target, invalidates the authorization
key, and exits.
- The requester resumes from UMH_WAIT_PROC, calls
complete_request_key(), and revokes the authorization key.
request_key_auth_revoke() sets its payload pointer to NULL.
- The descendant loads NULL and dereferences rka->cred.
This NULL dereference can oops the kernel. RCU delays payload disposal
but does not prevent the pointer from being cleared.
Load the payload with dereference_key_rcu() and require a non-NULL
result before validating the authorization key and searching its saved
credentials. A non-NULL payload and its credentials remain alive for
the caller's RCU read-side section; a cleared payload skips the fallback
search and follows the existing error selection.
KASAN report as below:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
RIP: 0010:search_process_keyrings_rcu+0x32b/0x790
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-03). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.Each input and its source, and whom BOD 26-04 binds: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it