In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads
atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c
unconditionally dereferences 8 bytes at payload_addr(pkt):
value = *(u64 *)payload_addr(pkt);
check_rkey() previously accepted an ATOMIC_WRITE request with pktlen ==
resid == 0 because the length validation only compared pktlen against
resid. A remote initiator that sets the RETH length to 0 therefore reaches
atomic_write_reply() with a zero-byte logical payload, and the responder
reads sizeof(u64) bytes from past the logical end of the packet into
skb->head tailroom, then writes those 8 bytes into the attacker's MR via
rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel
tailroom per probe (the other 4 bytes are the packet's own trailing ICRC).
IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is
protocol-invalid. Hoist a strict length check into check_rkey() so the
responder never reaches the unchecked dereference, and keep the existing
WRITE-family length logic for the normal RDMA WRITE path.
Reproduced on mainline with an unmodified rxe driver: a sustained
zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer
bytes into the attacker's MR, including recognisable kernel strings and
partial kernel-direct-map pointer words. With this patch applied the
responder rejects the PDU and the MR stays all-zero.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-19). 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
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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