CVE-2026-80839

UNRATEDCVSS · not yet scored

Also known asEUVD-2026-71289 (ENISA EUVD) · GHSA-676r-cqgf-36vf (GitHub Security Advisories)Source: ENISA EUVD

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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:

batman-adv: reject unrepresentable multicast TVLV offsets

The network and transport header fields in struct sk_buff are 16-bit offsets from skb->head, and U16_MAX is reserved as the unset transport header value. batadv_tvlv_call_handler() sets both fields from a received multicast TVLV without checking whether the TVLV end is representable.

If the end offset exceeds the field's range, skb_set_transport_header() truncates it so that the transport header precedes the network header. The negative difference is then returned by skb_network_header_len() as a large u32. batadv_mcast_forw_packet() consequently accepts an oversized multicast tracker and accesses memory beyond the skb data.

Add skb_set_transport_header_careful(), an offset-aware counterpart to skb_reset_transport_header_careful(), which validates the final head-relative offset before assigning it. Use the new helper in batadv_tvlv_call_handler() and reject unrepresentable TVLVs before setting the network header.

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
6th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

EG Severity
Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the BOD 26-04 block below.

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

September 4, 2026

Last Modified

October 19, 2026

Vendor Advisories for CVE-2026-80839(1)

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
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
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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
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Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (172 versions)
  • every version up to 7.1.13-1: fixed in 7.1.13-1
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Data Freshness Timeline

(refreshed 8× in last 7d / 45× 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.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 2 repeat rows among the latest 73 are merged into the row they repeat.

  1. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-25 13:59 UTCEG score recompute
  4. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  6. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-19 09:25 UTCNVD update
  11. 2026-10-19 09:23 UTCEG score recompute
  12. 2026-10-19 09:23 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  13. 2026-10-19 08:58 UTCMITRE cvelistV5
  14. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  15. 2026-10-18 03:09 UTCEG score recompute
  16. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  17. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  18. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  19. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  20. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  21. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  22. 2026-10-12 14:57 UTCEG score recompute
  23. 2026-10-11 19:21 UTCEG score recompute
  24. 2026-10-11 16:37 UTCEG score recompute
  25. 2026-10-11 13:55 UTCEG score recompute
Show 46 more
  1. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  2. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  3. 2026-10-10 04:30 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  4. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  5. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  6. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  7. 2026-10-07 05:02 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  8. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  9. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  10. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  11. 2026-10-04 06:04 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  12. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  13. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  14. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  15. 2026-10-01 07:06 UTCEG score recompute
  16. 2026-10-01 07:06 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  17. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  18. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  19. 2026-09-28 08:09 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  20. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  21. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  22. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  23. 2026-09-25 09:11 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  24. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  25. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  26. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  27. 2026-09-22 10:13 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  28. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  30. 2026-09-19 11:15 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  31. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  32. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  33. 2026-09-16 12:18 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  34. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  35. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  36. 2026-09-13 13:20 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  37. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  38. 2026-09-10 14:22 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  39. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  40. 2026-09-07 15:22 UTCEG score recompute
  41. 2026-09-07 15:22 UTCGHSA enrichmentGHSA-676r-cqgf-36vf
  42. 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  43. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  44. 2026-09-04 16:22 UTCNVD update
  45. 2026-09-04 16:05 UTCEG score recompute
  46. 2026-09-04 16:04 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-80839?
CVE-2026-80839 is a vulnerability whose severity is not yet rated; its CVE record was published on September 4, 2026. In the Linux kernel, the following vulnerability has been resolved: batman-adv: reject unrepresentable multicast TVLV offsets The network and transport header fields in struct sk_buff are 16-bit offsets from skb->head, and U16_MAX is reserved as the unset transport header value.…
When was the CVE record for CVE-2026-80839 published?
The CVE record for CVE-2026-80839 was published on September 4, 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 19, 2026; the record at its source may have been updated since.
Is CVE-2026-80839 actively exploited?
CVE-2026-80839 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-80839?
A fix for CVE-2026-80839 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-80839 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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