CVE-2026-53587

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (41st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-63547 (ENISA EUVD)Source: ENISA EUVD

7.5EG
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).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, libgit2 performs a fixed-size strncmp in set_data in src/libgit2/transports/smart_pkt.c without first verifying that the smart-protocol pkt-line capability buffer contains 14 bytes. A malicious Git server can make bytes after the pkt-line complete object-format=, causing format_str to advance beyond the pkt-line and the following memchr length calculation to underflow. The resulting heap out-of-bounds walk can crash a client during the first refs-advertisement packet over HTTP, HTTPS, SSH, or the Git protocol. This issue is fixed in versions 1.8.6 and 1.9.5.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
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 public PoC (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
0.5%
EPSS %ILE
41st
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-09). 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 public PoC (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

August 20, 2026

Last Modified

October 26, 2026

Advisory Details (6)

Auto-updated Aug 20, 2026
Patch available. Sources: github_release, github, github_commit.
GitHub release Patch Available

libgit2 v1.9.5

Patch available: libgit2/libgit2 v1.9.5

https://github.com/libgit2/libgit2/releases/tag/v1.9.5
GitHub release Patch Available

libgit2 v1.8.6

Patch available: libgit2/libgit2 v1.8.6

https://github.com/libgit2/libgit2/releases/tag/v1.8.6
GitHub commit

commit d7a9fb87f504 (libgit2/libgit2)

Fix landed in libgit2/libgit2 commit d7a9fb87f504 — awaiting tagged release

https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640
GitHub commit Patch Available

commit affda60c10fc (libgit2/libgit2)

Patch available: libgit2/libgit2 v1.9.5 (contains commit affda60c10fc)

https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3
GitHub commit Patch Available

commit 2c0ce8c0132a (libgit2/libgit2)

Patch available: libgit2/libgit2 v1.8.6 (contains commit 2c0ce8c0132a)

https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e
GitHub advisoryMentions a patch (unverified)

libgit2 <= 1.9.4 - Unauthenticated network-reachable heap out-of-bounds read in transports/smart_pkt.c:set_data · Advisory · libgit2/libgit2 · GitHub

https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm

Patch Availability(7)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibgit2-fixtures (1.7.2+ds-1ubuntu3.1) @ noble2026-10-26ubuntu
redhatrust-0:1.75.0-1.el9_4.12026-09-21redhat
redhatrust-0:1.84.1-1.el9_6.12026-09-21redhat
redhatrust-0:1.84.1-1.el10_0.42026-09-21redhat
redhatrust-0:1.92.0-2.el9_82026-09-14redhat
redhatrust-0:1.92.0-2.el10_22026-09-14redhat
redhatlibgit2-main-1.9.7-1.hum12026-08-25redhat

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

(5 across 5 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
libgit2—
  • every version up to 1.9.6-r0: fixed in 1.9.6-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
libgit2—
  • every version up to 1.9.6-r0: fixed in 1.9.6-r0
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
libgit21.5.1+ds-1 ... 1.9.7+ds-1 (32 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
libgit21.9.0+ds-2
  • every version up to 1.9.0+ds-2+deb13u1: fixed in 1.9.0+ds-2+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
libgit21.9.0+ds-2 ... 1.9.4+ds-1 (13 versions)
  • every version up to 1.9.6+ds-1: fixed in 1.9.6+ds-1
—

Weakness Classification(4)

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

Additional Vendor Advisories

(1)

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 8× in last 7d / 35× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 237 rows 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 137 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:53 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-11-10 08:15 UTCEchelonGraph re-scored
  6. 2026-11-10 08:15 UTCVendor advisory
  7. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  8. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  9. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  11. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  12. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  14. 2026-11-02 21:20 UTCEchelonGraph re-scored
  15. 2026-11-02 21:20 UTCVendor advisory
  16. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  17. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  19. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  20. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  21. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  22. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  23. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  24. 2026-10-26 10:26 UTCEchelonGraph re-scored
  25. 2026-10-26 10:26 UTCVendor advisory
Show 75 more
  1. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-25 14:20 UTCEchelonGraph re-scored
  3. 2026-10-24 19:30 UTCEchelonGraph re-scored
  4. 2026-10-24 19:30 UTCVendor advisory
  5. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  7. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  12. 2026-10-18 03:31 UTCEchelonGraph re-scored
  13. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-10-17 08:36 UTCEchelonGraph re-scored
  15. 2026-10-17 08:36 UTCVendor advisory
  16. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  18. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  19. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  20. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  21. 2026-10-12 15:57 UTCEchelonGraph re-scored
  22. 2026-10-11 19:40 UTCEchelonGraph re-scored
  23. 2026-10-11 16:55 UTCEchelonGraph re-scored
  24. 2026-10-11 14:18 UTCEchelonGraph re-scored
  25. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  26. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  27. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  28. 2026-10-09 08:22 UTCEchelonGraph re-scored
  29. 2026-10-09 08:22 UTCVendor advisory
  30. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  31. 2026-10-08 05:17 UTCEchelonGraph re-scored
  32. 2026-10-08 05:17 UTCVendor advisory
  33. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  34. 2026-10-07 07:20 UTCVendor advisory
  35. 2026-10-06 19:30 UTCEchelonGraph re-scored
  36. 2026-10-06 19:30 UTCVendor advisory
  37. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  38. 2026-10-06 07:52 UTCEchelonGraph re-scored
  39. 2026-10-06 07:52 UTCVendor advisory
  40. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  41. 2026-10-05 17:08 UTCVendor advisory
  42. 2026-10-05 04:58 UTCEchelonGraph re-scored
  43. 2026-10-05 04:58 UTCVendor advisory
  44. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  45. 2026-10-04 16:04 UTCVendor advisory
  46. 2026-10-04 04:24 UTCVendor advisory
  47. 2026-10-03 16:46 UTCEchelonGraph re-scored
  48. 2026-10-03 16:46 UTCVendor advisory
  49. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  50. 2026-10-02 21:00 UTCEchelonGraph re-scored
  51. 2026-10-02 21:00 UTCVendor advisory
  52. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  53. 2026-10-02 09:12 UTCVendor advisory
  54. 2026-10-01 21:28 UTCEchelonGraph re-scored
  55. 2026-10-01 21:28 UTCVendor advisory
  56. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  57. 2026-10-01 08:09 UTCVendor advisory
  58. 2026-09-30 20:31 UTCEchelonGraph re-scored
  59. 2026-09-30 20:31 UTCVendor advisory
  60. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  61. 2026-09-30 08:12 UTCEchelonGraph re-scored
  62. 2026-09-30 08:12 UTCVendor advisory
  63. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  64. 2026-09-29 02:55 UTCEchelonGraph re-scored
  65. 2026-09-29 02:55 UTCVendor advisory
  66. 2026-09-28 15:16 UTCEchelonGraph re-scored
  67. 2026-09-28 15:16 UTCVendor advisory
  68. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  69. 2026-09-28 03:35 UTCVendor advisory
  70. 2026-09-27 15:55 UTCEchelonGraph re-scored
  71. 2026-09-27 15:55 UTCVendor advisory
  72. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  73. 2026-09-27 02:58 UTCEchelonGraph re-scored
  74. 2026-09-27 02:58 UTCVendor advisory
  75. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 50th percentile

Frequently asked(5)

What is CVE-2026-53587?
CVE-2026-53587 is a high-severity vulnerability; its CVE record was published on August 20, 2026. libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, libgit2 performs a fixed-size strncmp in set_data in src/libgit2/transports/smart_pkt.c without first…
When was the CVE record for CVE-2026-53587 published?
The CVE record for CVE-2026-53587 was published on August 20, 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 26, 2026; the record at its source may have been updated since.
Is CVE-2026-53587 actively exploited?
CVE-2026-53587 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53587?
CVE-2026-53587 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-53587?
A fix for CVE-2026-53587 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-53587 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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