CVE-2026-23247 (GCVE-0-2026-23247)

Vulnerability from cvelistv5 – Published: 2026-03-18 10:05 – Updated: 2026-05-23 16:04
VLAI
Title
tcp: secure_seq: add back ports to TS offset
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: secure_seq: add back ports to TS offset This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 28ee1b746f493b7c62347d714f58fbf4f70df4f0 , < eae2f14ab2efccdb7480fae7d42c4b0116ef8805 (git)
Affected: 28ee1b746f493b7c62347d714f58fbf4f70df4f0 , < 46e5b0d7cf55821527adea471ffe52a5afbd9caf (git)
Affected: 28ee1b746f493b7c62347d714f58fbf4f70df4f0 , < 165573e41f2f66ef98940cf65f838b2cb575d9d1 (git)
Affected: 443fac9f2618b93cbc5ab068dc594530236b3a23 (git)
Affected: 4.10.14 , < 4.11 (semver)
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Linux Linux Affected: 4.11
Unaffected: 0 , < 4.11 (semver)
Unaffected: 6.18.17 , ≤ 6.18.* (semver)
Unaffected: 6.19.7 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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          "programFiles": [
            "include/net/secure_seq.h",
            "include/net/tcp.h",
            "net/core/secure_seq.c",
            "net/ipv4/syncookies.c",
            "net/ipv4/tcp_input.c",
            "net/ipv4/tcp_ipv4.c",
            "net/ipv6/syncookies.c",
            "net/ipv6/tcp_ipv6.c"
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}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.