CVE-2026-98374

UNRATEDCVSS · not yet scoredTrending — 5 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()

When tcp_send_synack() replaces the cloned SYN skb at the head of the retransmit queue with a copy, it frees the original with tcp_rtx_queue_unlink_and_free() and only repairs tp->highest_sack. tp->retransmit_skb_hint keeps pointing at the freed skbuff_fclone_cache object.

The dangling hint is read in tcp_verify_retransmit_hint() and used as the root of the rbtree walk in tcp_xmit_retransmit_queue(). An unprivileged TFO client (sendmsg(MSG_FASTOPEN)) can arm the hint with an attacker-supplied ICMP fragmentation-needed message, after which a simultaneous open frees the armed SYN skb:

BUG: KASAN: slab-use-after-free in tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) Read of size 4 at addr ffff88800604d928 by task swapper/1/0 Call Trace: tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316) tcp_simple_retransmit (net/ipv4/tcp_input.c:3158) tcp_v4_err (net/ipv4/tcp_ipv4.c:587)

Sync the hint to the copy.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.2%
EPSS %ILE
4th
KEV
Not listed

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 7, 2026

Last Modified

October 7, 2026

References (7)

Vendor Advisories for CVE-2026-98374(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.3~rc6-1~exp1 (361 versions)
  • every version on: no fix on record
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Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.3~rc6-1~exp1 (184 versions)
  • every version on: no fix on record
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Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (182 versions)
  • every version up to 7.2.9-1: fixed in 7.2.9-1
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Data Freshness Timeline

(refreshed 15× in last 7d / 15× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-12 14:38 UTCEG score recompute
  4. 2026-10-11 19:10 UTCEG score recompute
  5. 2026-10-11 16:24 UTCEG score recompute
  6. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  7. 2026-10-11 13:37 UTCEG score recompute
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-10 10:58 UTCEG score recompute
  10. 2026-10-10 10:58 UTCGHSA enrichmentGHSA-2q84-vc4j-mp23
  11. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  13. 2026-10-07 13:24 UTCNVD update
  14. 2026-10-07 13:17 UTCEG score recompute
  15. 2026-10-07 13:16 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-98374?
CVE-2026-98374 is a vulnerability whose severity is not yet rated; its CVE record was published on October 7, 2026. In the Linux kernel, the following vulnerability has been resolved: tcp: fix use-after-free of retransmitskbhint in tcpsendsynack() When tcpsendsynack() replaces the cloned SYN skb at the head of the retransmit queue with a copy, it frees the original with tcprtxqueueunlinkandfree() and only…
When was the CVE record for CVE-2026-98374 published?
The CVE record for CVE-2026-98374 was published on October 7, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 7, 2026; the record at its source may have been updated since.
Is CVE-2026-98374 actively exploited?
CVE-2026-98374 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-98374?
A fix for CVE-2026-98374 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-98374 are linked in the Vendor Advisories panel on this page.

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