Answer in brief
CVE-2026-72502 records a High severity (CVSS 7.5) vulnerability in tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <560b33b434e922ef97f9ff23aa2e909ef7aacd5c || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <21f69ac1879bb970588d5e7c12a96e6542f7c1a7 || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <c0db3dc2ac323b6c4b76adede3b355a9daa6dea8 || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <572fff10819dfc359298d1f774839e76a4d96f93 || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <8e6214a530c03e341dc1b0a846c8f2b716b3551a || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <d774cdbda6634a78d0f2baf201ee5a8c57f3bc0e || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <a210791f33345aa87187f7d7a9f3b9b7f4a28e6d || >=3953c46c3ac7eef31a9935427371c6f54a22f1ba <2bf43d0e2e6a27d52a7d624e2d6b9116972e8a22 | 560b33b434e922ef97f9ff23aa2e909ef7aacd5c, 21f69ac1879bb970588d5e7c12a96e6542f7c1a7, c0db3dc2ac323b6c4b76adede3b355a9daa6dea8, 572fff10819dfc359298d1f774839e76a4d96f93, 8e6214a530c03e341dc1b0a846c8f2b716b3551a, d774cdbda6634a78d0f2baf201ee5a8c57f3bc0e, a210791f33345aa87187f7d7a9f3b9b7f4a28e6d, 2bf43d0e2e6a27d52a7d624e2d6b9116972e8a22 |
| Linux/Linuxgeneric | 4.8 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF) When MTU is large, ip6_default_advmss() can return IPV6_MAXPLEN (65535). This is interpreted by TCP as mss_clamp, allowing the MSS to reach 65535. However, 0xFFFF is also used as a magic value GSO_BY_FRAGS in the kernel. If a TCP packet with gso_size=0xFFFF is passed to skb_segment(), it will be mistakenly treated as GSO_BY_FRAGS, leading to a NULL pointer dereference because local TCP packets do not use frag_list. Fix this by returning min(IPV6_MAXPLEN, GSO_BY_FRAGS - 1) (65534) from ip6_default_advmss() when MTU is large. Also update the stale comment in ip6_default_advmss() which suggested that IPV6_MAXPLEN is returned to mean "any MSS".
Quoted source text, attributed separately from HOL analysis.