CVE-2026-53176

Aliases:UBUNTU-CVE-2026-53176DEBIAN-CVE-2026-53176CGA-3pfq-3jrg-gj77CGA-64f6-2vg6-33hmCGA-74xg-9w4q-hv78CGA-7fcf-xcr2-prwjCGA-987v-x5c2-c6mfCGA-c8pw-38c7-wxjvCGA-g7r9-rrwc-69m8CGA-j93v-v567-qxvpCGA-pg75-99m4-vg8qCGA-r26m-p76f-v57gCGA-v6v9-gfgx-j39mCGA-xf7r-453r-72vg
Advisory lineage Upstream: 0 Downstream: 56
Modified
Published: 25 Jun 2026, 08:38
Last modified:18 Sept 2026, 12:04

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
0.73% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

25 Jun 2026, 08:38
Published
Vulnerability first disclosed
18 Sept 2026, 12:04
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN In drivers/infiniband/ulp/isert/ib_isert.c, isert_login_recv_done() computes the login request payload length as wc->byte_len minus ISER_HEADERS_LEN with no lower bound, and login_req_len is a signed int. A remote iSER initiator can post a login Send work request carrying fewer than ISER_HEADERS_LEN (76) bytes, so the subtraction underflows and login_req_len becomes negative. isert_rx_login_req() then reads that negative length back into a signed int, takes size = min(rx_buflen, MAX_KEY_VALUE_PAIRS), and because the min() is signed it keeps the negative value; the value is then passed as the memcpy() length and sign-extended to a multi-gigabyte size_t. The copy into the 8192-byte login->req_buf runs far out of bounds and faults, crashing the target node. The login phase precedes iSCSI authentication, so no credentials are required to reach this path. Reject any login PDU shorter than ISER_HEADERS_LEN before the subtraction, mirroring the existing early return on a failed work completion, so login_req_len can never go negative. The upper bound was already safe: a posted login buffer cannot deliver more than ISER_RX_PAYLOAD_SIZE, so the difference stays at or below MAX_KEY_VALUE_PAIRS and the existing min() clamps it; only the missing lower bound needs to be added.

CVSS Metrics

  • v4.0•HIGH•Score: 8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.73%• Percentile: 53%

Techniques & Countermeasures

  • CWE-191•Integer Underflow (Wrap or Wraparound)

    The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

  • CWE-839•Numeric Range Comparison Without Minimum Check

    The product checks a value to ensure that it is less than or equal to a maximum, but it does not also verify that the value is greater than or equal to the minimum.

Affected Systems

  • chainguard•linux-aws-6.12

    < 6.12.95-r0

  • chainguard•linux-aws-6.18

    < 6.18.38-r0

  • chainguard•linux-azure-6.18

    < 6.18.38-r0

  • chainguard•linux-gcp-6.12

    < 6.12.95-r0

  • chainguard•linux-gcp-6.18

    < 6.18.38-r0

  • chainguard•linux-gcp-6.18-bootc-boot-installed

    < 6.18.38-r0

  • chainguard•linux-qemu-6.12

    < 6.12.95-r0

  • chainguard•linux-qemu-6.18

    < 6.18.38-r0

  • chainguard•linux-qemu-6.18-bootc-boot-installed

    < 6.18.38-r0

  • chainguard•linux-qemu-melange

    < 6.18.38-r0

  • chainguard•linux-vmware-6.12

    < 6.12.95-r0

  • chainguard•linux-vmware-6.18

    < 6.18.38-r0

  • debian•linux

    < 5.10.259-1 | < 6.1.176-1 | < 6.12.94-1 | < 7.0.13-1

  • debian•linux-6.1

    < 6.1.176-1~deb11u1

  • ubuntu•linux

    all | < 3.13.0-215.266 | < 4.4.0-284.318 | < 4.15.0-254.266 | < 5.4.0-234.254 | < 5.15.0-187.197 | < 6.8.0-137.137 | all | < 7.0.0-29.29

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 4.4.0-1157.163 | < 4.4.0-1195.210 | < 4.15.0-1195.208 | < 5.4.0-1162.173 | < 5.15.0-1113.120 | < 6.8.0-1062.65 | all | < 7.0.0-1010.10

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    all | < 5.15.0-1114.121~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    all | < 5.4.0-1162.173~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    all

  • ubuntu•linux-aws-6.17

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    all | < 6.8.0-1062.65~22.04.2

  • ubuntu•linux-aws-7.0

    all | < 7.0.0-1010.10~24.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2133.139 | all | < 5.4.0-1163.174+fips1 | < 5.15.0-1113.120+fips1 | < 6.8.0-1062.65+fips1

  • ubuntu•linux-aws-hwe

    all | < 4.15.0-1195.208~16.04.1

  • ubuntu•linux-azure

    all | < 4.15.0-1205.220~14.04.1 | < 4.15.0-1205.220~16.04.1 | all | < 5.4.0-1167.173 | < 5.15.0-1118.127 | < 6.8.0-1064.72 | all | < 7.0.0-1011.11

  • ubuntu•linux-azure-4.15

    < 4.15.0-1205.220

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    all | < 5.15.0-1119.128~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    all | < 5.4.0-1167.173~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    all

  • ubuntu•linux-azure-6.17

    < 6.17.0-1022.22

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1064.72~22.04.1

  • ubuntu•linux-azure-7.0

    all

  • ubuntu•linux-azure-edge

    all

Showing first 50 affected entries in server-rendered view.

References (60)