CVE-2026-12087

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 2026-06-16. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 4 sources updated this week

Also known asEUVD-2026-37009 (ENISA EUVD) · GHSA-q5cv-5vf6-95gp (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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.

Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to version 2.041 or later."

Socket versions before 2.041 for Perl have an out-of-bounds heap read.

In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the preceding multiaddr argument instead. Both addresses occupy a 4-byte field, so a valid multiaddr lets a source of any length pass the check, and the source is then copied into the 4-byte imr_sourceaddr field with a fixed-size copy. A source shorter than 4 bytes is not rejected, and the copy reads up to 3 bytes past the end of its buffer.

Calling pack_ip_mreq_source() with a source value shorter than 4 bytes copies adjacent heap memory into the returned packed structure.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.6% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
47th
KEV
Not listed

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

The EG score (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

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

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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

June 15, 2026

Last Modified

October 25, 2026

Advisory Details (3)

Auto-updated Aug 1, 2026
Patch available.
Web page

oss-security - CVE-2026-12087: Socket versions before 2.041 for Perl have an out-of-bounds heap read

http://www.openwall.com/lists/oss-security/2026/06/15/10

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuperl-modules-5.22 (5.22.1-9ubuntu0.9+esm3) @ xenial2026-11-02ubuntu
ubuntuperl-modules-5.40 (5.40.1-7ubuntu0.3) @ resolute2026-11-02ubuntu
ubuntuperl-modules-5.38 (5.38.2-3.2ubuntu0.4) @ noble2026-11-02ubuntu
redhatperl-socket-main-2.041-1.hum12026-04-28redhat

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

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
libsocket-perl2.031-1 ... 2.041-1 (9 versions)
  • every version on: no fix on record
—
perl5.32.1-4 ... 5.44.0-1 (59 versions)
  • every version on: no fix on record
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
libsocket-perl2.036-1 ... 2.043-1 (6 versions)
  • every version on: no fix on record
—
perl5.36.0-7, 5.36.0-7+deb12u1, 5.36.0-7+deb12u2, 5.36.0-7+deb12u3
  • every version up to 5.36.0-7+deb12u4: fixed in 5.36.0-7+deb12u4
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
libsocket-perl2.038-1
  • every version up to 2.038-1+deb13u1: fixed in 2.038-1+deb13u1
—
perl5.40.1-6
  • every version up to 5.40.1-6+deb13u1: fixed in 5.40.1-6+deb13u1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
libsocket-perl2.038-1, 2.040-1
  • every version up to 2.041-1: fixed in 2.041-1
—
perl5.40.1-6 ... 5.42.2-3 (9 versions)
  • every version up to 5.42.3-1: fixed in 5.42.3-1
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 28× in last 7d / 99× 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 813 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 713 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-02 11:45 UTCEG score recompute
  2. 2026-11-02 11:45 UTCVendor advisory
  3. 2026-11-02 11:45 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  4. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  5. 2026-11-01 10:36 UTCEG score recompute
  6. 2026-11-01 10:36 UTCVendor advisory
  7. 2026-11-01 10:36 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  8. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  9. 2026-10-31 09:27 UTCEG score recompute
  10. 2026-10-31 09:27 UTCVendor advisory
  11. 2026-10-31 09:27 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  12. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  13. 2026-10-30 08:18 UTCEG score recompute
  14. 2026-10-30 08:18 UTCVendor advisory
  15. 2026-10-30 08:18 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  17. 2026-10-29 07:09 UTCEG score recompute
  18. 2026-10-29 07:09 UTCVendor advisory
  19. 2026-10-29 07:09 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  20. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  21. 2026-10-28 06:00 UTCEG score recompute
  22. 2026-10-28 06:00 UTCVendor advisory
  23. 2026-10-28 06:00 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  24. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  25. 2026-10-27 04:52 UTCEG score recompute
Show 75 more
  1. 2026-10-27 04:52 UTCVendor advisory
  2. 2026-10-27 04:52 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  4. 2026-10-25 23:28 UTCVendor advisory
  5. 2026-10-25 23:28 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  6. 2026-10-25 19:47 UTCEG score recompute
  7. 2026-10-25 19:47 UTCVendor advisory
  8. 2026-10-25 19:47 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  10. 2026-10-25 14:50 UTCEG score recompute
  11. 2026-10-24 18:37 UTCEG score recompute
  12. 2026-10-24 18:37 UTCVendor advisory
  13. 2026-10-24 18:37 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  14. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-10-23 17:29 UTCEG score recompute
  16. 2026-10-23 17:29 UTCVendor advisory
  17. 2026-10-23 17:29 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  18. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  19. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-22 16:20 UTCEG score recompute
  21. 2026-10-22 16:20 UTCVendor advisory
  22. 2026-10-22 16:20 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  23. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  24. 2026-10-21 14:40 UTCEG score recompute
  25. 2026-10-21 14:40 UTCVendor advisory
  26. 2026-10-21 14:40 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  27. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  28. 2026-10-20 13:31 UTCEG score recompute
  29. 2026-10-20 13:31 UTCVendor advisory
  30. 2026-10-20 13:31 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  31. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  32. 2026-10-19 12:21 UTCEG score recompute
  33. 2026-10-19 12:21 UTCVendor advisory
  34. 2026-10-19 12:21 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  35. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  36. 2026-10-18 10:36 UTCVendor advisory
  37. 2026-10-18 10:36 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  38. 2026-10-18 05:04 UTCEG score recompute
  39. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  40. 2026-10-17 09:22 UTCEG score recompute
  41. 2026-10-17 09:22 UTCVendor advisory
  42. 2026-10-17 09:22 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  43. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  44. 2026-10-16 08:14 UTCEG score recompute
  45. 2026-10-16 08:14 UTCVendor advisory
  46. 2026-10-16 08:14 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  47. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  48. 2026-10-15 07:04 UTCEG score recompute
  49. 2026-10-15 07:04 UTCVendor advisory
  50. 2026-10-15 07:04 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  51. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  52. 2026-10-14 02:54 UTCEG score recompute
  53. 2026-10-14 02:54 UTCVendor advisory
  54. 2026-10-14 02:54 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  55. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  56. 2026-10-12 23:01 UTCVendor advisory
  57. 2026-10-12 23:01 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  58. 2026-10-12 16:36 UTCEG score recompute
  59. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  60. 2026-10-12 09:50 UTCVendor advisory
  61. 2026-10-12 09:50 UTCGHSA enrichmentGHSA-q5cv-5vf6-95gp · GitHub severity CRITICAL · GitHub CVSS 9.1
  62. 2026-10-11 20:12 UTCEG score recompute
  63. 2026-10-11 18:24 UTCEG score recompute
  64. 2026-10-11 14:58 UTCEG score recompute
  65. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  66. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  67. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  68. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  69. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  70. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  71. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  72. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  73. 2026-10-03 16:48 UTCOSV refresh
  74. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  75. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile

Frequently asked(5)

What is CVE-2026-12087?
CVE-2026-12087 is a critical-severity vulnerability; its CVE record was published on June 15, 2026. Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the preceding multiaddr argument instead. Both addresses occupy a…
When was the CVE record for CVE-2026-12087 published?
The CVE record for CVE-2026-12087 was published on June 15, 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 25, 2026; the record at its source may have been updated since.
Is CVE-2026-12087 actively exploited?
CVE-2026-12087 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-2026-12087?
CVE-2026-12087 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-12087?
A fix for CVE-2026-12087 is available: update to the fixed version the vendor names in its advisory. Fixed versions, as the CVE record's CNA (CPAN Security Group) states them: "Upgrade to version 2.041 or later." The vendor advisories EchelonGraph has for CVE-2026-12087 are linked in the Vendor Advisories panel on this page.

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