CVE-2026-80603

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-28. A secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read

parse_dcc() treats data_end as an inclusive end pointer, but its only caller passes data_limit = ib_ptr + datalen, which points one past the last valid byte.

The newline search loop iterates while tmp <= data_end, so when no newline is present, *tmp is read at tmp == data_end, one byte beyond the region filled by skb_header_pointer().

irc_buffer is kmalloc'd as MAX_SEARCH_SIZE + 1 bytes and datalen is capped at MAX_SEARCH_SIZE, so the stray read does not fault. The byte is uninitialized or stale; if it contains an ASCII digit, simple_strtoul will consume it and produce a wrong DCC IP or port in the conntrack expectation. The extra allocation byte is also a fragile guard: if the cap or allocation size changes, this becomes a real out-of-bounds read.

Change the loop and its post-loop check to use strict less-than, consistent with the caller's exclusive-end convention. Update the function comment accordingly.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
41
EG Risk 41/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity91% × 45%
The EG Score, 9.1 of 10.
Exploitation0.6% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.6%
EPSS %ILE
47th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

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

August 28, 2026

Last Modified

August 29, 2026

Advisory Details (8)

Auto-updated Sep 15, 2026
Patch available.
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ef6400ca25a13fd6dedbe8ef4a1d0979bbbfe88a
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/eeef3b81f449560653662df2dde6f6fe247c5365
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/aff589556ed772cb1c0c2d7b4d91ec45c0c39416
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/abb8c32b88ea3f46beb68c34fe9a3ac8ed664e7e
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/910c33e4a8c046c3cc1fa5a465a4d41a1bb398f1
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/437e0a3854b3a44ec15afa9ab88ec215adf3a2fd
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2b70f61f569bb29acb380e6f616a1bbdee15668f
Web page

netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2393f0bd7a467ad475598f3a5b9de27ca36e3037

Vendor Advisories for CVE-2026-80603(1)

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

Patch Availability(11)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)
  • every version up to 6.1.180-1: fixed in 6.1.180-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)
  • every version up to 6.12.100-1: fixed in 6.12.100-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (160 versions)
  • every version up to 7.1.5-1: fixed in 7.1.5-1
—

All Vendor Advisories

(11)

Data Freshness Timeline

(refreshed 38× in last 7d / 211× 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.

Showing the most recent 100 of 344 refreshes on record for this CVE.

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. None are among the latest 100 rows. The 244 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 08:50 UTCEG score recompute
  2. 2026-10-14 08:50 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  4. 2026-10-13 04:45 UTCEG score recompute
  5. 2026-10-13 04:45 UTCVendor advisory
  6. 2026-10-13 04:45 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  7. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  8. 2026-10-12 14:57 UTCEG score recompute
  9. 2026-10-12 05:22 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-10-11 19:21 UTCEG score recompute
  11. 2026-10-11 16:37 UTCEG score recompute
  12. 2026-10-11 13:55 UTCEG score recompute
  13. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  14. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  15. 2026-10-10 13:42 UTCVendor advisory
  16. 2026-10-10 13:42 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  17. 2026-10-10 09:39 UTCVendor advisory
  18. 2026-10-10 09:39 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  19. 2026-10-10 05:18 UTCVendor advisory
  20. 2026-10-10 05:18 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  21. 2026-10-10 01:22 UTCEG score recompute
  22. 2026-10-10 01:22 UTCVendor advisory
  23. 2026-10-10 01:22 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  25. 2026-10-09 07:02 UTCVendor advisory
Show 75 more
  1. 2026-10-09 07:02 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  2. 2026-10-09 02:47 UTCEG score recompute
  3. 2026-10-09 02:47 UTCVendor advisory
  4. 2026-10-09 02:47 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  5. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  6. 2026-10-08 08:51 UTCVendor advisory
  7. 2026-10-08 08:51 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  8. 2026-10-08 04:55 UTCVendor advisory
  9. 2026-10-08 04:55 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-10-08 00:59 UTCEG score recompute
  11. 2026-10-08 00:59 UTCVendor advisory
  12. 2026-10-08 00:59 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  13. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  14. 2026-10-07 08:58 UTCVendor advisory
  15. 2026-10-07 08:58 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-10-07 05:01 UTCVendor advisory
  17. 2026-10-07 05:01 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  18. 2026-10-07 01:06 UTCVendor advisory
  19. 2026-10-07 01:06 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-10-06 20:31 UTCVendor advisory
  21. 2026-10-06 20:31 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  22. 2026-10-06 15:56 UTCEG score recompute
  23. 2026-10-06 15:56 UTCVendor advisory
  24. 2026-10-06 15:55 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  25. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  26. 2026-10-06 11:24 UTCVendor advisory
  27. 2026-10-06 11:24 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  28. 2026-10-06 07:29 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  29. 2026-10-06 00:49 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  30. 2026-10-05 20:45 UTCEG score recompute
  31. 2026-10-05 20:45 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  32. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  33. 2026-10-05 16:50 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  34. 2026-10-05 11:34 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  35. 2026-10-05 07:36 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  36. 2026-10-05 03:41 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  37. 2026-10-04 23:32 UTCEG score recompute
  38. 2026-10-04 23:32 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  39. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  40. 2026-10-04 19:37 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  41. 2026-10-04 13:22 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  42. 2026-10-04 09:05 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  43. 2026-10-04 05:09 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  44. 2026-10-04 01:14 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  45. 2026-10-03 19:20 UTCEG score recompute
  46. 2026-10-03 19:20 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  47. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  48. 2026-10-03 14:24 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  49. 2026-10-03 06:54 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  50. 2026-10-03 02:58 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  51. 2026-10-02 22:59 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  52. 2026-10-02 18:50 UTCEG score recompute
  53. 2026-10-02 18:50 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  54. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  55. 2026-10-02 14:46 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  56. 2026-10-02 10:12 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  57. 2026-10-02 06:17 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  58. 2026-10-02 00:40 UTCEG score recompute
  59. 2026-10-02 00:39 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  60. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  61. 2026-10-01 19:50 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  62. 2026-10-01 13:20 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  63. 2026-10-01 09:24 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  64. 2026-10-01 05:28 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  65. 2026-10-01 00:59 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  66. 2026-09-30 19:51 UTCEG score recompute
  67. 2026-09-30 19:51 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  68. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  69. 2026-09-30 11:48 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  70. 2026-09-30 07:53 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  71. 2026-09-30 03:57 UTCEG score recompute
  72. 2026-09-30 03:57 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  73. 2026-09-29 14:13 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  74. 2026-09-29 09:55 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1
  75. 2026-09-29 05:12 UTCGHSA enrichmentGHSA-66q8-v4rr-393c · GitHub severity CRITICAL · GitHub CVSS 9.1

Frequently asked(5)

What is CVE-2026-80603?
CVE-2026-80603 is a critical-severity vulnerability; its CVE record was published on August 28, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: nfconntrackirc: fix parse_dcc() off-by-one OOB read parsedcc() treats dataend as an inclusive end pointer, but its only caller passes datalimit = ibptr + datalen, which points one past the last valid byte. The newline…
When was the CVE record for CVE-2026-80603 published?
The CVE record for CVE-2026-80603 was published on August 28, 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 August 29, 2026; the record at its source may have been updated since.
Is CVE-2026-80603 actively exploited?
CVE-2026-80603 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (47th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-80603?
CVE-2026-80603 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-80603?
A fix for CVE-2026-80603 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-80603 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-80603

Explore →

Is Your Infrastructure Affected by CVE-2026-80603?

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