MIT krb5 through 1.22.2 contains a NULL pointer dereference vulnerability in the KDC's get_pac_princ_with_realm() that returns success while leaving the client principal NULL on malformed names. A malicious or compromised cross-realm trusted KDC can send an S4U2Proxy request with a PAC carrying a malformed client name to crash krb5kdc and deny authentication.
CVE-2026-107708
“—” beside the score: it is equal to the CVSS score beside it.
Score 4.9 from GitHub Security Advisory published 2026-10-08. A secondary CVSS source baseline 4.9; sources differ by 0.0.
Also known asEUVD-2026-95255 (ENISA EUVD) · GHSA-wc3c-9xc9-26g8 (GitHub Security Advisories)Source: ENISA EUVD
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 4.9
- EG Score
- 4.9MEDIUMhigh confidence
- EG Risk
- 22EG Risk 22/100
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)Severity49% × 45%Impact severity (EG Severity): CVSS 4.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.5% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (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
- 0.5%
- EPSS %ILE
- 44th
- 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 (4.9): severity, escalated by confirmed exploitation. This CVE's 4.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). 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 every mission impact level.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, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (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.
The score's inputs: 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 8, 2026
Last Modified
October 14, 2026
Advisory Details (6)
Auto-updated Oct 8, 2026MIT krb5 through 1.22.2 KDC NULL Pointer Dereference via S4U2Proxy PAC | Advisories | VulnCheck
https://www.vulncheck.com/advisories/mit-krb5-through-1.22.2-kdc-null-pointer-dereference-via-s4u2proxy-packrb5/src/kdc/kdc_util.c at krb5-1.22.2-final · krb5/krb5 · GitHub
https://github.com/krb5/krb5/blob/krb5-1.22.2-final/src/kdc/kdc_util.c#L639-L676commit a88a18cafa10 (krb5/krb5)
Fix landed in krb5/krb5 commit a88a18cafa10 — awaiting tagged release
https://github.com/krb5/krb5/commit/a88a18cafa1040a0c4f9c8d08288fc98831ec86dcommit f6e2c397ceda (krb5/krb5)
Fix landed in krb5/krb5 commit f6e2c397ceda — awaiting tagged release
https://github.com/krb5/krb5/commit/f6e2c397ceda6467ebbaab8ed66d4895c9f1d6a7Fix error propagation in get_pac_princ_with_realm
Fix merged in krb5/krb5 PR #1510 on 2026-05-19 — awaiting tagged release
https://github.com/krb5/krb5/pull/1510Vendor Advisories for CVE-2026-107708(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 / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | krb5-main-1.22.2-10.3.hum1 | 2026-10-11 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| krb5 | 1.20.1-2 ... 1.22.1-3 (23 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| krb5 | 1.21.3-5 ... 1.22.1-3 (6 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| krb5 | 1.21.3-5, 1.22.1-1, 1.22.1-2, 1.22.1-2.1, 1.22.1-3 |
| — |
Weakness Classification(1)
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 10× in last 7d / 54× 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.
- 2026-11-02 16:43 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-29 14:56 UTCEG score recompute
- 2026-10-29 14:56 UTCVendor advisory
- 2026-10-29 14:56 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
- 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-25 14:54 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-23 08:36 UTCEG score recompute
- 2026-10-23 08:36 UTCVendor advisory
- 2026-10-23 08:36 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-18 05:07 UTCEG score recompute
- 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
Show 29 moreShow fewer
- 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-14 02:26 UTCEG score recompute
- 2026-10-14 02:26 UTCVendor advisory
- 2026-10-14 02:26 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-14 01:36 UTCEG score recompute
- 2026-10-14 01:36 UTCVendor advisory
- 2026-10-14 01:36 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-12 16:38 UTCEG score recompute
- 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-11 23:11 UTCVendor advisory
- 2026-10-11 23:10 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-11 20:14 UTCEG score recompute
- 2026-10-11 18:26 UTCEG score recompute
- 2026-10-11 15:00 UTCEG score recompute
- 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-10 22:40 UTCEG score recompute
- 2026-10-10 22:40 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-09 22:10 UTCEG score recompute
- 2026-10-09 22:09 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-08 21:37 UTCEG score recompute
- 2026-10-08 21:37 UTCGHSA enrichmentGHSA-wc3c-9xc9-26g8 · GitHub CVSS 4.9
- 2026-10-08 21:20 UTCEG score recompute
- 2026-10-08 20:23 UTCEG score recomputeFirst assessed: 4.9 MEDIUM
- 2026-10-08 20:23 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:12:krb5
- CVE-2011-4862EG 10.0EPSS p100HIGH
- CVE-2011-0285EG 10.0EPSS p98HIGH
- CVE-2009-4212EG 10.0EPSS p95HIGH
- CVE-2009-0846EG 10.0EPSS p95HIGH
- CVE-2008-0947EG 10.0EPSS p95HIGH
- CVE-2007-5902EG 10.0EPSS p93HIGH
- CVE-2007-4743EG 10.0EPSS p92HIGH
- CVE-2007-3999EG 10.0EPSS p96HIGH
- CVE-2007-2442EG 10.0EPSS p96HIGH
- CVE-2007-0956EG 10.0EPSS p98HIGH
Frequently asked(5)
What is CVE-2026-107708?
When was CVE-2026-107708 made public?
Is CVE-2026-107708 actively exploited?
What is the CVSS score of CVE-2026-107708?
How do I remediate CVE-2026-107708?
Dependency Blast Radius
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