{"id":"CVE-2026-53176","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nIB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN\n\nIn drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done()\ncomputes the login request payload length…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nIB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN\n\nIn drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done()\ncomputes the login request payload length…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-191","CWE-839"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.10, < 5.10.259","linux_kernel >= 5.11, < 5.15.210","linux_kernel >= 5.16, < 6.1.176","linux_kernel >= 6.2, < 6.6.143","linux_kernel >= 6.7, < 6.12.94","linux_kernel >= 6.13, < 6.18.36","linux_kernel >= 6.19, < 7.0.13","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.13"],"published":"2026-06-25","updated":"2026-09-18","sourceUpdated":"2026-09-18T13:18:32.900","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53176","references":[{"url":"https://git.kernel.org/stable/c/1ca40b243277c9e88be5e00bd3e083f71aefb93e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/29e7b925ae6df64894e82ab6419994dc25580a8a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/75ee6e4aa096aa9e7b2dd5c8ff98356e30aceefb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bd22740d7f14cb1c0289444cfd2c8d2938667c1d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c1234229399f4af12c553b1b0ffd978eeba65548","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c5584e089b5af7b3bf8bd5e8ca0560cbf32b0a47","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/df422fd273c96c2ee5beb80fc21adc8c70c29260","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e8a013c0c3ca2f6708341a56612a3f6d6921620a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://access.redhat.com/errata/RHSA-2026:68507","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:68531","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:68532","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:68570","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-53176","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492741","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53176.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53176"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53176"},{"url":"https://lore.kernel.org/linux-cve-announce/2026062553-CVE-2026-53176-c8a7@gregkh/T"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00761,"epssPercentile":0.53858,"scores":{"nvd":9.8,"vendor":6.5,"cna":9.8},"ingestedAt":"2026-07-06T17:44:51.378Z","slug":"CVE-2026-53176","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nIB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN\n\nIn drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done()\ncomputes the login request payload length as wc->byte_len minus\nISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int.\nA remote iSER initiator can post a login Send work request carrying\nfewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows\nand login_req_len becomes negative.\n\nisert_rx_login_req() then reads that negative length back into a signed\nint, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the\nmin() is signed it keeps the negative value; the value is then passed as\nthe memcpy() length and sign-extended to a multi-gigabyte size_t. The\ncopy into the 8192-byte login->req_buf runs far out of bounds and\nfaults, crashing the target node. The login phase precedes iSCSI\nauthentication, so no credentials are required to reach this path.\n\nReject any login PDU shorter than ISER_HEADERS_LEN before the\nsubtraction, mirroring the existing early return on a failed work\ncompletion, so login_req_len can never go negative. The upper bound was\nalready safe: a posted login buffer cannot deliver more than\nISER_RX_PAYLOAD_SIZE, so the difference stays at or below\nMAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing\nlower bound needs to be added.\n\n## Affected\n\n- `linux_kernel >= 3.10, < 5.10.259`\n- `linux_kernel >= 5.11, < 5.15.210`\n- `linux_kernel >= 5.16, < 6.1.176`\n- `linux_kernel >= 6.2, < 6.6.143`\n- `linux_kernel >= 6.7, < 6.12.94`\n- `linux_kernel >= 6.13, < 6.18.36`\n- `linux_kernel >= 6.19, < 7.0.13`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.13`\n\n## Vendor advisories\n\n- **RHSA-2026:68507** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68507)\n- **RHSA-2026:68570** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68570)\n- **RHSA-2026:68531** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68531)\n- **RHSA-2026:68532** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68532)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-09-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53176.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}