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Review reviewCritical

CVE-2026-63887

Linux

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_che...

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

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_che...

Affected product and versions

Product
Linux
Affected versions
>= e48354ce078c079996f89d715dfa44814b4eba01 < cb84e974fb172bc71386289f37b78ea679410b39, >= e48354ce078c079996f89d715dfa44814b4eba01 < b19382dfc6e7dee6d3859ba44b6ca29e97a51627, >= e48354ce078c079996f89d715dfa44814b4eba01 < efe633e600a0ac68357206fede21b1ac8178f3b8, >= e48354ce078c079996f89d715dfa44814b4eba01 < 4e9f0c4a645c995bc75c06c7b3644254ffb4c76b, >= e48354ce078c079996f89d715dfa44814b4eba01 < 30bf335e8fe170322080ee001f05ca29c50680b3, >= e48354ce078c079996f89d715dfa44814b4eba01 < 594a40360012ce5f94c715d5e3b20fa3af7d525a, >= e48354ce078c079996f89d715dfa44814b4eba01 < 26e4a304b7e6f1338c675d527608d32549c091db, >= e48354ce078c079996f89d715dfa44814b4eba01 < bf33e01f88388c43e285492a63e539df6ffed64c, >= 3.1
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2026-63887 — Linux | SECUFOCUS NOW