CVE-2026-98303

UNRATEDCVSS · not yet scoredTrending — 4 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:

ipv4: icmp: reject RTN_UNREACHABLE input routes in icmp_route_lookup

When the forward output route cannot be used in icmp_route_lookup(), it enters the "reverse path" and calls ip_route_input() on fl4_dec.daddr, the original packet's source address.

ip_route_input() only returns an error for truly invalid packets. For unreachable addresses it will succeed and return an input route whose dst.output is set to ip_rt_bug(). The existing check only rejects RTN_LOCAL routes, so the RTN_UNREACHABLE route types can still be returned and later used for output, syzkaller triggering a WARN_ON_ONCE() in ip_rt_bug() as bellow:

------------[ cut here ]------------ WARNING: net/ipv4/route.c:1273 at ip_rt_bug+0x14/0x20 RIP: 0010:ip_rt_bug+0x14/0x20 Call Trace: ip_push_pending_frames+0xfa/0x100 __icmp_send+0x905/0xf10 ip_options_compile+0xc0/0xd0 ip_rcv_finish_core+0x321/0xae0 ip_rcv+0x1de/0x260 __netif_receive_skb_one_core+0x11a/0x130 netif_receive_skb+0x7b/0x260 tun_get_user+0x11bf/0x1c10 ------------[ cut here ]------------

Reject input route that is RTN_UNREACHABLE to fix it. The net warning is only printed for RTN_LOCAL, as RTN_UNREACHABLE is not the result of a race condition.

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
7th
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 6, 2026

Last Modified

October 6, 2026

References (6)

Vendor Advisories for CVE-2026-98303(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 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
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Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (183 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 (181 versions)
  • every version up to 7.2.8-1: fixed in 7.2.8-1
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Data Freshness Timeline

(refreshed 16× in last 7d / 21× 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% · 7th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-12 14:38 UTCEG score recompute
  4. 2026-10-11 23:47 UTCVendor advisory
  5. 2026-10-11 23:46 UTCGHSA enrichmentGHSA-hw8j-26f4-2863
  6. 2026-10-11 19:10 UTCEG score recompute
  7. 2026-10-11 16:25 UTCEG score recompute
  8. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-10-11 13:37 UTCEG score recompute
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-10-09 04:40 UTCEG score recompute
  13. 2026-10-09 04:40 UTCVendor advisory
  14. 2026-10-09 04:40 UTCGHSA enrichmentGHSA-hw8j-26f4-2863
  15. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-10-06 09:35 UTCGHSA enrichmentGHSA-hw8j-26f4-2863
  19. 2026-10-06 09:28 UTCNVD update
  20. 2026-10-06 08:54 UTCEG score recompute
  21. 2026-10-06 08:52 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-98303?
CVE-2026-98303 is a vulnerability whose severity is not yet rated; its CVE record was published on October 6, 2026. In the Linux kernel, the following vulnerability has been resolved: ipv4: icmp: reject RTNUNREACHABLE input routes in icmproute_lookup When the forward output route cannot be used in icmproutelookup(), it enters the "reverse path" and calls iprouteinput() on fl4_dec.daddr, the original packet's…
When was the CVE record for CVE-2026-98303 published?
The CVE record for CVE-2026-98303 was published on October 6, 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 6, 2026; the record at its source may have been updated since.
Is CVE-2026-98303 actively exploited?
CVE-2026-98303 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-98303?
A fix for CVE-2026-98303 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-98303 are linked in the Vendor Advisories panel on this page.

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