CVE-2026-80725

UNRATEDCVSS · not yet scoredTrending — 4 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%CVSS v2: —Exploit: None knownExposed: 0

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

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

net: gro: properly validate BIG TCP aggregation criteria

When GRO attempts to aggregate packets beyond GRO_LEGACY_MAX_SIZE (64KB), BIG TCP should only be permitted for plain IPv4 TCP and plain IPv6 TCP (with sufficient MAC header room to insert the temporary HBH jumbo header).

However, commit b1a78b9b9886 ("net: add support for ipv4 big tcp") loosened the check in skb_gro_receive(), leading to several issues:

  • skb_gro_receive() checked skb_headroom(p) instead of the actual space
before the MAC header (p->mac_header). Because skb_headroom(p) includes mac_len, crafted frames (e.g. injected via AF_PACKET) can pass the check with p->mac_header < 8 bytes. When ipv6_gro_complete() inserts the temporary HBH jumbo header, the memmove() starts before skb->head, causing an out-of-bounds write and wrapping skb->mac_header.
  • It allowed non-IP protocols such as software VLAN (ETH_P_8021Q /
ETH_P_8021AD) to aggregate beyond 64KB because p->protocol != ETH_P_IPV6 was true.
  • It checked p->encapsulation instead of NAPI_GRO_CB(skb)->encap_mark,
allowing encapsulated flows (e.g. SIT / IPv6-in-IPv4) to aggregate beyond 64KB.

Fix skb_gro_receive() to strictly enforce:

  • NAPI_GRO_CB(skb)->proto == IPPROTO_TCP
  • Not encapsulated (!NAPI_GRO_CB(skb)->encap_mark && !p->encapsulation)
  • Protocol must be either ETH_P_IP or ETH_P_IPV6
  • If ETH_P_IPV6, p->mac_header must be at least
sizeof(struct hop_jumbo_hdr)

Returning -E2BIG from skb_gro_receive() ensures that packets which cannot become BIG TCP are cleanly flushed at <= 64KB and delivered intact without dropping.

This issue does not exist in mainline (7.0+) because the subsystem was rewritten in commit 81be30c1f5f2 ("net/ipv6: Drop HBH for BIG TCP on RX side"), making this fix relevant only for older stable branches like 6.18.y.

CVSS v3
—
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
—
EG Risk
—
EPSS PROB
0%
EPSS %ILE
9%
KEV
Not listed

Published

August 29, 2026

Last Modified

August 29, 2026

References (5)

Vendor Advisories for CVE-2026-80725(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 4× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 07:22 UTCNVD update
  3. 2026-08-29 06:48 UTCEG score recompute
  4. 2026-08-29 06:47 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-80725?
CVE-2026-80725 is a publicly disclosed vulnerability published on August 29, 2026. In the Linux kernel, the following vulnerability has been resolved: net: gro: properly validate BIG TCP aggregation criteria When GRO attempts to aggregate packets beyond GROLEGACYMAX_SIZE (64KB), BIG TCP should only be permitted for plain IPv4 TCP and plain IPv6 TCP (with sufficient MAC header…
When was CVE-2026-80725 disclosed?
CVE-2026-80725 was first published in the National Vulnerability Database on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-80725 actively exploited?
CVE-2026-80725 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 91.2% of all scored CVEs.
How do I remediate CVE-2026-80725?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-80725, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-80725

Explore →

Is Your Infrastructure Affected by CVE-2026-80725?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs