Medium [CVE-2026-53176] Reject login PDUs shorter than ISER_HEADERS_LEN
This medium-severity Red Hat Linux advisory covers CVE-2026-53176 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Get an email when Red Hat Linux publishes the next one.
VulniPulse checks Red Hat Linux's security advisories around the clock and emails you new ones with the severity, the fixed version and the vendor's link. First month free, then US$15/month; we email you before the first charge.
Summary
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.
Affected products named by the advisory: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Enterprise Linux 7; and 1 more.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
- kernel-0:6.12.0-211.56.1.el10_2
- kernel-rt-0:4.18.0-553.164.1.rt7.505.el8_10
- kernel-0:4.18.0-553.164.1.el8_10
- kernel-0:5.14.0-687.49.1.el9_8
- RHSA-2026:68507
- RHSA-2026:68532
- RHSA-2026:68531
- RHSA-2026:68570
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
Mitigation checklist
- To mitigate this issue, prevent module ib_isert from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Official advisory · high-confidence parse· fetched 5 days ago·verify at source
More Red Hat Linux advisories
- CVE-2026-111497Oct 22, 2026Out-of-Bounds Write in Google Brotli Decoder
- CVE-2026-109619Oct 21, 2026fatal error handling retains stale request state leading to use-after-free
- CVE-2026-109618Oct 21, 2026OOM bailout during request parsing leads to memory corruption and RCE
- CVE-2026-97229Oct 13, 2026integer overflow issue in CI/CD regular expression compiler
- CVE-2026-64849Aug 17, 2026Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed
- CVE-2026-53362Jul 4, 2026account for fraggap on the paged allocation path
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.