CVE-2026-97984

UNRATEDCVSS · not yet scoredTrending — 6 sources updated this week
—
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

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

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

net: ipv6: Fix UDP length overflow with PMTU discover and big MTU

This commit bounds cork->base.fragsize to IP6_MAX_MTU for UDP sockets to avoid a possible overflow of UDP length that triggers a WARN in udp_set_len_short when setsockopt IPV6_MTU_DISCOVER is set to IPV6_PMTUDISC_DO or IPV6_PMTUDISC_PROBE, and a large packet is sent over a netdev with an unusually large MTU.

Steps to reproduce (included in the new selftest):

  • Set device MTU bigger than IP6_MAX_MTU. cork->base.fragsize will be
set to that MTU in ip6_setup_cork.
  • Set IPV6_MTU_DISCOVER to IPV6_PMTUDISC_PROBE or IPV6_PMTUDISC_DO. It
lets maxnonfragsize be set to device MTU (cork->fragsize) in __ip6_append_data, rather than to IP6_MAX_MTU.
  • Send 65528 bytes of payload (+8 bytes of UDP header, +40 bytes of
IPv6 header). Device MTU allows it (it's only one byte bigger than IP6_MAX_MTU, and the device MTU is bigger than that).
  • The UDP length in the built packet is 65536, which overflows the
16-bit length field and triggers the WARN in udp_set_len_short.

To avoid breaking sending UDP jumbograms over raw IPv6 sockets, limit the change to UDP sockets only.

The original overflow bug with IPv6 and IPV6_PMTUDISC_DO seems to predate git history (verified reproduction on 2.6.21), was fixed later, and then reappeared in commit 427faee167bc ("net: ipv6: introduce ip6_dst_mtu_maybe_forward"), which is chosen as the Fixes tag here. The overflow with IPV6_PMTUDISC_PROBE reproduces since its introduction in commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE").

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
5th
KEV
Not listed

Published

September 25, 2026

Last Modified

October 3, 2026

References (5)

Vendor Advisories for CVE-2026-97984(2)

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

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (180 versions)
  • every version up to 7.2.7-1: fixed in 7.2.7-1
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Data Freshness Timeline

(refreshed 19× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-10-04 23:23 UTCEPSS rescore
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-03 11:28 UTCVendor advisory
  4. 2026-10-03 11:28 UTCGHSA enrichment
  5. 2026-10-03 11:26 UTCNVD update
  6. 2026-10-03 11:15 UTCVendor advisory
  7. 2026-10-03 11:15 UTCGHSA enrichment
  8. 2026-10-03 11:10 UTCMITRE cvelistV5
  9. 2026-10-02 17:57 UTCEPSS rescore
  10. 2026-10-02 01:07 UTCEG score recompute
  11. 2026-10-02 01:07 UTCVendor advisory
  12. 2026-10-02 01:07 UTCGHSA enrichment
  13. 2026-10-01 19:51 UTCEPSS rescore
  14. 2026-09-30 15:04 UTCEPSS rescore
  15. 2026-09-28 18:23 UTCEG score recompute
  16. 2026-09-28 18:23 UTCVendor advisory
  17. 2026-09-28 18:23 UTCGHSA enrichment
  18. 2026-09-28 13:52 UTCEPSS rescore
  19. 2026-09-28 13:52 UTCEPSS rescore
  20. 2026-09-27 13:49 UTCEPSS rescore
  21. 2026-09-26 15:59 UTCEPSS rescore
  22. 2026-09-25 11:30 UTCNVD update
  23. 2026-09-25 10:30 UTCEG score recompute
  24. 2026-09-25 10:27 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-97984?
CVE-2026-97984 is a publicly disclosed vulnerability published on September 25, 2026. In the Linux kernel, the following vulnerability has been resolved: net: ipv6: Fix UDP length overflow with PMTU discover and big MTU This commit bounds cork->base.fragsize to IP6MAXMTU for UDP sockets to avoid a possible overflow of UDP length that triggers a WARN in udpsetlenshort when setsockopt…
When was CVE-2026-97984 disclosed?
CVE-2026-97984 was first published on September 25, 2026, with the most recent update on October 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-97984 actively exploited?
CVE-2026-97984 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-97984?
No fix for CVE-2026-97984 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-97984 are linked in the Vendor Advisories panel on this page.

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