# IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN

CVE record · `CVE-2026-53176`

- **Identifiers:** `CVE-2026-53176`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Weakness (CWE):** [CWE-839](https://cwe.mitre.org/data/definitions/839.html)
- **Tags:** [CWE-839](https://agentprime.io/advisories/tag/cwe-839.md)
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 25 Jun 2026
- **Updated:** 19 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 25 Jun 2026, 08:38 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before 75ee6e4aa096aa9e7b2dd5c8ff98356e30aceefb` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before e8a013c0c3ca2f6708341a56612a3f6d6921620a` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before bd22740d7f14cb1c0289444cfd2c8d2938667c1d` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before c1234229399f4af12c553b1b0ffd978eeba65548` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before c5584e089b5af7b3bf8bd5e8ca0560cbf32b0a47` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before df422fd273c96c2ee5beb80fc21adc8c70c29260` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before 1ca40b243277c9e88be5e00bd3e083f71aefb93e` (git)
  - affected: `b8d26b3be8b33682cf163274ed07479a70554633 to before 29e7b925ae6df64894e82ab6419994dc25580a8a` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `3.10`
  - unaffected: `before 3.10` (semver)
  - unaffected: `5.10.259 to 5.10.*, inclusive` (semver)
  - unaffected: `5.15.210 to 5.15.*, inclusive` (semver)
  - unaffected: `6.1.176 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.143 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.94 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.36 to 6.18.*, inclusive` (semver)
  - unaffected: `7.0.13 to 7.0.*, inclusive` (semver)
  - unaffected: `7.1 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (Linux) (used for this record)
- 6.5 Medium, CVSS 3.1: `CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`, from ADP (redhat-SADP)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0076, the 55th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 25 Jun 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-53176](https://www.cve.org/CVERecord?id=CVE-2026-53176)
- [NVD: CVE-2026-53176](https://nvd.nist.gov/vuln/detail/CVE-2026-53176)

### References from the CNA

- <https://git.kernel.org/stable/c/75ee6e4aa096aa9e7b2dd5c8ff98356e30aceefb>
- <https://git.kernel.org/stable/c/e8a013c0c3ca2f6708341a56612a3f6d6921620a>
- <https://git.kernel.org/stable/c/bd22740d7f14cb1c0289444cfd2c8d2938667c1d>
- <https://git.kernel.org/stable/c/c1234229399f4af12c553b1b0ffd978eeba65548>
- <https://git.kernel.org/stable/c/c5584e089b5af7b3bf8bd5e8ca0560cbf32b0a47>
- <https://git.kernel.org/stable/c/df422fd273c96c2ee5beb80fc21adc8c70c29260>
- <https://git.kernel.org/stable/c/1ca40b243277c9e88be5e00bd3e083f71aefb93e>
- <https://git.kernel.org/stable/c/29e7b925ae6df64894e82ab6419994dc25580a8a>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-53176>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-53176/>. Everything for agents: <https://agentprime.io/llms.txt>.