In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf
iscsi_encode_text_output() concatenates "key=value\0" records into
login->rsp_buf, an 8192-byte kzalloc(MAX_KEY_VALUE_PAIRS) buffer
allocated in iscsit_alloc_login_setup_buffer(). The three sprintf() call
sites in this function (lines 1398, 1411, 1424 in v7.1-rc2) never check
the remaining buffer capacity:
*length += sprintf(output_buf, "%s=%s", er->key, er->value);
*length += 1;
output_buf = textbuf + *length;
The 8192-byte ceiling at iscsi_target_check_login_request() bounds the
*input* Login PDU payload, but a single PDU can carry up to 2048 minimal
four-byte "a=b\0" pairs, each unknown key expanding to a 16-byte
"a=NotUnderstood\0" output record via iscsi_add_notunderstood_response().
2048 * 16 = 32 KiB of output into an 8 KiB buffer, producing a ~24 KiB
heap overrun in the kmalloc-8k slab.
The fix introduces a static iscsi_encode_text_record() helper that uses
snprintf() with a per-call bounds check against the remaining buffer,
and threads a u32 textbuf_size parameter through
iscsi_encode_text_output(). Both call sites in
iscsi_target_handle_csg_zero() (PHASE_SECURITY) and
iscsi_target_handle_csg_one() (PHASE_OPERATIONAL) pass
MAX_KEY_VALUE_PAIRS. On overflow the encoder logs the condition, calls
iscsi_release_extra_responses() to drop queued records, and returns -1;
both caller sites now emit ISCSI_STATUS_CLS_INITIATOR_ERR /
ISCSI_LOGIN_STATUS_INIT_ERR via iscsit_tx_login_rsp() before returning,
so the initiator sees an explicit failed-login response rather than a
silent connection drop. (Prior to this patch only the PHASE_OPERATIONAL
caller did that; the PHASE_SECURITY caller is converted to the same
shape.)
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: 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 total (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)3 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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