CVE-2026-85977

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreHIGH confidence

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

Score 5.3 from GitHub Security Advisory published 2026-10-16. A secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-103020 (ENISA EUVD) · GHSA-vc3g-5238-rmmw (GitHub Security Advisories)Source: ENISA EUVD

5.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (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: 0.4%CVSS: 5.3Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

A flaw was found in libtirpc. A remote attacker can exploit this vulnerability by sending specially crafted PMAPPROC_DUMP replies to a client application that uses the pmap_getmaps() function against an attacker-controlled host. This unbounded decoding can lead to excessive memory and CPU allocation, causing the client process to experience a Denial of Service (DoS) due to resource exhaustion.

CVSS v3
5.3
EG Score
5.3MEDIUMhigh confidence
EG Risk
40
EG Risk 40/100

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)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.4%
EPSS %ILE
36th
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 (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.

EG Severity
5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS. 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; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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 public PoC (CISA Vulnrichment) · Automatable no (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)60 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 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

October 16, 2026

Last Modified

October 19, 2026

Advisory Details (2)

Auto-updated Oct 16, 2026
Patch available. Sources: redhat.
Red Hat

2478979 – (CVE-2026-85977) CVE-2026-85977 libtirpc: libtirpc: Denial of Service via unbounded memory allocation during portmapper response decoding

https://bugzilla.redhat.com/show_bug.cgi?id=2478979
Red HatMentions a patch (unverified)

CVE-2026-85977 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-85977

Vendor Advisories for CVE-2026-85977(2)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatlibtirpc-main-1.3.8-0.1.hum12026-10-11redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 25× 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.

  1. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-25 13:55 UTCEG score recompute
  4. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  5. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  6. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  7. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  9. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  10. 2026-10-19 15:26 UTCEG score recompute
  11. 2026-10-19 15:26 UTCVendor advisory
  12. 2026-10-19 15:25 UTCGHSA enrichmentGHSA-vc3g-5238-rmmw · GitHub CVSS 5.3
  13. 2026-10-19 14:28 UTCEG score recompute
  14. 2026-10-19 14:28 UTCVendor advisory
  15. 2026-10-19 14:28 UTCGHSA enrichmentGHSA-vc3g-5238-rmmw · GitHub CVSS 5.3
  16. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  17. 2026-10-18 03:05 UTCEG score recompute
  18. 2026-10-17 21:27 UTCEG score recompute
  19. 2026-10-17 21:27 UTCGHSA enrichmentGHSA-vc3g-5238-rmmw · GitHub CVSS 5.3
  20. 2026-10-17 20:56 UTCEG score recompute
  21. 2026-10-17 20:56 UTCGHSA enrichmentGHSA-vc3g-5238-rmmw · GitHub CVSS 5.3
  22. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  23. 2026-10-16 19:45 UTCEG score recompute
  24. 2026-10-16 18:22 UTCEG score recomputeFirst assessed: 5.3 MEDIUM
  25. 2026-10-16 18:22 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-85977?
CVE-2026-85977 is a medium-severity vulnerability; its CVE record was published on October 16, 2026. A flaw was found in libtirpc. A remote attacker can exploit this vulnerability by sending specially crafted PMAPPROCDUMP replies to a client application that uses the pmapgetmaps() function against an attacker-controlled host. This unbounded decoding can lead to excessive memory and CPU allocation,…
When was CVE-2026-85977 made public?
CVE-2026-85977 was made public on October 16, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on October 16, 2026. EchelonGraph's copy of the record carries a last-modified date of October 19, 2026; the record at its source may have been updated since.
Is CVE-2026-85977 actively exploited?
CVE-2026-85977 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-85977?
CVE-2026-85977 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-85977?
A fix for CVE-2026-85977 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-85977 are linked in the Vendor Advisories panel on this page.

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